From 55a248518720a483ae153cd82765f871dd82d4b9 Mon Sep 17 00:00:00 2001
From: Laura Kasian <lkasian@synopsys.com>
Date: Mon, 2 Nov 2026 15:15:45 -0700
Subject: [PATCH 1/7] feat: show client-mode geo highlight from server scene

---
 src/ansys/visor/viewer/app/trame/local_app.py |  30 ++++-
 src/ansys/visor/viewer/app/visor_vtk_local.py |   6 +-
 .../runtime/requests/pixel_scale_payload.py   |  11 ++
 .../visor/viewer/renderer/local_renderer.py   |   2 +-
 .../viewer/renderer/pipeline_renderer.py      |   8 ++
 .../visor/viewer/renderer/server_renderer.py  |   7 -
 .../visor/viewer/vtk/scene/local_scene.py     |   8 ++
 .../WasmRendererWidgetTriggers.test.tsx       |  62 +++++++++
 .../visor-client/src/renderer/IRenderer.ts    |   4 +-
 .../src/renderer/SceneTriggerSends.ts         |   5 +
 .../visor-client/src/renderer/WasmRenderer.ts |   9 +-
 .../visor/visor-client/src/wasm/VtkScene.js   | 120 ------------------
 tests/unit/app/test_scene_trigger_app.py      |  45 ++++++-
 tests/unit/renderer/test_local_renderer.py    |  17 +++
 tests/unit/vtk/scene/test_local_scene.py      |  14 ++
 15 files changed, 206 insertions(+), 142 deletions(-)
 create mode 100644 src/ansys/visor/viewer/models/runtime/requests/pixel_scale_payload.py

diff --git a/src/ansys/visor/viewer/app/trame/local_app.py b/src/ansys/visor/viewer/app/trame/local_app.py
index aefe75da..1d727a0c 100644
--- a/src/ansys/visor/viewer/app/trame/local_app.py
+++ b/src/ansys/visor/viewer/app/trame/local_app.py
@@ -1,13 +1,19 @@
 from logging import Logger
+from typing import Protocol
 
 from trame.app.core import Server
 from trame.decorators import TrameApp, trigger
 from vtk import vtkObject
 
-from ansys.visor.viewer.app.trame.scene_trigger_app import SceneMutationApi, SceneTriggerApp
+from ansys.visor.viewer.app.trame.scene_trigger_app import (
+    SceneMutationApi,
+    SceneTriggerApp,
+    parse_payload,
+)
 from ansys.visor.viewer.config import settings
 from ansys.visor.viewer.core.visor_enums import RenderingMode
 from ansys.visor.viewer.core.visor_logging import VisorDefaultLogger
+from ansys.visor.viewer.models.runtime.requests.pixel_scale_payload import SetPixelScalePayload
 
 logger = VisorDefaultLogger(__name__)
 
@@ -15,6 +21,12 @@
 vtkObject.GlobalWarningDisplayOff()
 
 
+class LocalSceneMutationApi(SceneMutationApi, Protocol):
+    """The scene surface LocalApp's triggers call: the shared one plus the client-only pixel scale."""
+
+    def set_pixel_scale(self, pixel_scale: float) -> None: ...
+
+
 @TrameApp()
 class LocalApp(SceneTriggerApp):
     """
@@ -28,6 +40,7 @@ class LocalApp(SceneTriggerApp):
         pick_geometry: picks the geometry for rendering
         perf_report_wasm: reports the performance of the wasm update cycle
         perf_report_server_update: reports the performance of the server update cycle
+        set_pixel_scale: sets the device pixel ratio the geometry highlight is drawn at
         set_only_cookie: sets a cookie on the server (note: Trame server only allows a single cookie header)
     """
     def __init__(
@@ -37,7 +50,7 @@ def __init__(
             standalone: bool = True,
             trame_logger: Logger | None = None,
             pick_geometry=None,
-            scene_mutation_api: SceneMutationApi | None = None,
+            scene_mutation_api: LocalSceneMutationApi | None = None,
     ):
         # Callable for sub-geometry picking (optional), local-only.
         self._pick_geometry = pick_geometry
@@ -61,6 +74,19 @@ def pick_geometry(self, actor_wasm_id, cell_id, mode: str, world_x: float, world
             return {"found": False}
         return self._pick_geometry(actor_wasm_id, cell_id, mode, world_x, world_y, world_z)
 
+    @trigger("set_pixel_scale")
+    @parse_payload(SetPixelScalePayload)
+    def set_pixel_scale(self, payload) -> None:
+        """Frontend -> Backend: the client reports its device pixel ratio for the geometry highlight.
+
+        Server mode learns the same ratio from the remote-canvas size report,
+        so only client mode registers this.
+        """
+        api = self._mutation_api("set_pixel_scale", payload)
+        if api is None:
+            return
+        api.set_pixel_scale(payload.scale)
+
     @trigger("perf_report_wasm")
     def perf_report_wasm(self, payload: dict):
         """
diff --git a/src/ansys/visor/viewer/app/visor_vtk_local.py b/src/ansys/visor/viewer/app/visor_vtk_local.py
index ea982ad9..690734b2 100644
--- a/src/ansys/visor/viewer/app/visor_vtk_local.py
+++ b/src/ansys/visor/viewer/app/visor_vtk_local.py
@@ -51,9 +51,9 @@ def _initialize_rendering(self, standalone: bool, trame_log_dir: str | None) ->
                 world_x,
                 world_y,
                 world_z: self._scene.pick_geometry(actor_wasm_id, cell_id, mode, world_x, world_y, world_z),
-            # The scene satisfies LocalApp's SceneMutationApi protocol
-            # structurally: the six per-part coordinator methods carry exactly
-            # the names and signatures the triggers call.
+            # The scene satisfies LocalApp's LocalSceneMutationApi protocol
+            # structurally: the coordinator methods carry exactly the names
+            # and signatures the triggers call.
             scene_mutation_api=self._scene,
         )
 
diff --git a/src/ansys/visor/viewer/models/runtime/requests/pixel_scale_payload.py b/src/ansys/visor/viewer/models/runtime/requests/pixel_scale_payload.py
new file mode 100644
index 00000000..d9f38e1d
--- /dev/null
+++ b/src/ansys/visor/viewer/models/runtime/requests/pixel_scale_payload.py
@@ -0,0 +1,11 @@
+"""Model for the ``set_pixel_scale`` trigger payload."""
+
+from typing import Annotated
+
+from pydantic import BaseModel, Field
+
+
+class SetPixelScalePayload(BaseModel):
+    """set_pixel_scale payload: the client's device pixels per CSS pixel, finite and positive."""
+
+    scale: Annotated[float, Field(gt=0, allow_inf_nan=False)]
diff --git a/src/ansys/visor/viewer/renderer/local_renderer.py b/src/ansys/visor/viewer/renderer/local_renderer.py
index ae83a5d7..6b3335cb 100644
--- a/src/ansys/visor/viewer/renderer/local_renderer.py
+++ b/src/ansys/visor/viewer/renderer/local_renderer.py
@@ -200,7 +200,7 @@ def _present_geometry_highlight(self) -> None:
         self.push_without_rebuild()
 
     def _initial_highlight_pixel_scale(self) -> float:
-        """1.0: the client draws its own overlay here, so the actor's sizes are not shown."""
+        """1.0 until the client reports its device pixel ratio."""
         return 1.0
 
     # ------------------------------------------------------------------
diff --git a/src/ansys/visor/viewer/renderer/pipeline_renderer.py b/src/ansys/visor/viewer/renderer/pipeline_renderer.py
index eef73f8b..d25dd521 100644
--- a/src/ansys/visor/viewer/renderer/pipeline_renderer.py
+++ b/src/ansys/visor/viewer/renderer/pipeline_renderer.py
@@ -539,6 +539,14 @@ def show_geometry_highlight(self, pick: GeometryPick) -> None:
         pick.highlight_with(self._geometry_highlight)
         self._present_geometry_highlight()
 
+    def set_pixel_scale(self, pixel_scale: float) -> None:
+        """Rescale the geometry highlight to this many device pixels per CSS pixel; requests no frame and pushes nothing.
+
+        Server mode's resize path, which calls this, schedules its own frame.
+        In client mode the next highlight shown carries the new size.
+        """
+        self._geometry_highlight.set_pixel_scale(pixel_scale)
+
     # ------------------------------------------------------------------
     # Internal init helpers
     # ------------------------------------------------------------------
diff --git a/src/ansys/visor/viewer/renderer/server_renderer.py b/src/ansys/visor/viewer/renderer/server_renderer.py
index bdffb5fc..df72e7bf 100644
--- a/src/ansys/visor/viewer/renderer/server_renderer.py
+++ b/src/ansys/visor/viewer/renderer/server_renderer.py
@@ -88,13 +88,6 @@ def set_viewport_size(self, width: int, height: int) -> None:
         self._render_window_interactor.UpdateSize(width, height)
         self._orientation_widget.fit_to_window(width, height)
 
-    def set_pixel_scale(self, pixel_scale: float) -> None:
-        """Rescale the geometry highlight to this many device pixels per CSS pixel.
-
-        Requests no frame: the resize path that calls this schedules its own.
-        """
-        self._geometry_highlight.set_pixel_scale(pixel_scale)
-
     def set_background_rgb(self, background_rgb: tuple[float, float, float]) -> None:
         """Clear to this colour from the next frame.
 
diff --git a/src/ansys/visor/viewer/vtk/scene/local_scene.py b/src/ansys/visor/viewer/vtk/scene/local_scene.py
index 3abc2f74..654659dd 100644
--- a/src/ansys/visor/viewer/vtk/scene/local_scene.py
+++ b/src/ansys/visor/viewer/vtk/scene/local_scene.py
@@ -78,6 +78,14 @@ def pick_geometry(self, actor_wasm_id, cell_id, mode, world_x, world_y, world_z)
             actor_wasm_id, cell_id, mode, (world_x, world_y, world_z)
         )
 
+    def set_pixel_scale(self, pixel_scale: float) -> None:
+        """Draw the geometry highlight at this many device pixels per CSS pixel; no push, no notify.
+
+        The next highlight shown carries the new size to the client.
+        """
+        with self._vtk_lock:
+            self._renderer.set_pixel_scale(pixel_scale)
+
     def pick_geometry_in_view(self, view: "PickView", x: int, y: int, mode: str) -> "GeometryPick":
         """Find the geometry feature under a pixel of a client's view, under the scene lock."""
         with self._vtk_lock:
diff --git a/src/ansys/visor/visor-client/src/jest-tests/WasmRendererWidgetTriggers.test.tsx b/src/ansys/visor/visor-client/src/jest-tests/WasmRendererWidgetTriggers.test.tsx
index 2c73a02f..142fd96a 100644
--- a/src/ansys/visor/visor-client/src/jest-tests/WasmRendererWidgetTriggers.test.tsx
+++ b/src/ansys/visor/visor-client/src/jest-tests/WasmRendererWidgetTriggers.test.tsx
@@ -31,6 +31,14 @@ import type { TrameTriggerSender } from '../renderer/IRenderer';
  * Also pinned: `resizeAsync` fits the orientation widget to the window as it
  * stands after the scene resize.
  *
+ * Also pinned: `resizeAsync` reports the window's device pixel ratio to
+ * `set_pixel_scale`, so the server draws the geometry highlight at the size
+ * the wasm canvas shows it.
+ *
+ * Also pinned: a geometry highlight and a clear each send
+ * `set_geometry_highlight` with the pick, so the server draws and drops it;
+ * the scene no longer draws one of its own.
+ *
  * Modelled on `WasmRendererPartTriggers.test.tsx`, which does the same for
  * the six per-part sends.
  */
@@ -416,3 +424,57 @@ describe('WasmRenderer fits the orientation widget on resize', () => {
         expect(orientationRepresentation.SetSize).toHaveBeenCalledWith([105, 105]);
     });
 });
+
+/** Let the sends that are not awaited run to completion. */
+async function settle() {
+    await new Promise((resolve) => setTimeout(resolve, 0));
+}
+
+describe('WasmRenderer reports its device pixel ratio on resize', () => {
+    let originalDevicePixelRatio: number;
+
+    beforeEach(() => {
+        originalDevicePixelRatio = window.devicePixelRatio;
+        Object.defineProperty(window, 'devicePixelRatio', { configurable: true, value: 2 });
+    });
+
+    afterEach(() => {
+        Object.defineProperty(window, 'devicePixelRatio', {
+            configurable: true,
+            value: originalDevicePixelRatio,
+        });
+    });
+
+    test("resizeAsync sends set_pixel_scale with the window's device pixel ratio", async () => {
+        const sender = makeSender();
+        const { renderer } = await makeRenderer(sender);
+
+        await renderer.resizeAsync();
+        await settle();
+
+        expect(sender.mock.calls).toStrictEqual([['set_pixel_scale', { scale: 2 }]]);
+    });
+});
+
+describe('WasmRenderer geometry highlight sends', () => {
+    test('a highlight then a clear each send set_geometry_highlight with the pick', async () => {
+        const sender = makeSender();
+        const { renderer } = await makeRenderer(sender);
+
+        await renderer.setGeometryHighlightAsync({
+            found: true,
+            mode: 'vertex',
+            position: [1, 2, 3],
+        });
+        renderer.clearGeometryHighlight();
+        await settle();
+
+        expect(sender.mock.calls).toStrictEqual([
+            [
+                'set_geometry_highlight',
+                { pick: { found: true, mode: 'vertex', position: [1, 2, 3] } },
+            ],
+            ['set_geometry_highlight', { pick: { found: false } }],
+        ]);
+    });
+});
diff --git a/src/ansys/visor/visor-client/src/renderer/IRenderer.ts b/src/ansys/visor/visor-client/src/renderer/IRenderer.ts
index 7fe1c5ae..c6b078f3 100644
--- a/src/ansys/visor/visor-client/src/renderer/IRenderer.ts
+++ b/src/ansys/visor/visor-client/src/renderer/IRenderer.ts
@@ -75,13 +75,13 @@ export type GeometryPickMode = 'vertex' | 'edge' | 'face';
 
 export interface IRenderer {
     // ---- Canvas / lifecycle -------------------------------------------------
-    /** DOM element hosting the render output (canvas + overlay). */
+    /** DOM element hosting the render output. */
     readonly domElement: HTMLDivElement;
     /** Kick a frame flush. Wasm: wasm.update() + Render(). Server: no-op. */
     renderAsync(): Promise<void>;
     /** Resize output to its container. Call after container size changes. */
     resizeAsync(): Promise<void>;
-    /** Drop listeners, wasm observers, overlay canvas, RPC sessions, etc. */
+    /** Drop listeners, wasm observers, RPC sessions, etc. */
     dispose(): void;
 
     // ---- Camera (all reads async; state may live off-thread / off-box) ------
diff --git a/src/ansys/visor/visor-client/src/renderer/SceneTriggerSends.ts b/src/ansys/visor/visor-client/src/renderer/SceneTriggerSends.ts
index c98c5347..309758de 100644
--- a/src/ansys/visor/visor-client/src/renderer/SceneTriggerSends.ts
+++ b/src/ansys/visor/visor-client/src/renderer/SceneTriggerSends.ts
@@ -162,4 +162,9 @@ export class SceneTriggerSends {
     async sendGeometryHighlightAsync(pick: PickGeometryResult): Promise<void> {
         await this.#sendWidgetTriggerAsync('set_geometry_highlight', { pick });
     }
+
+    /** Send the device pixels per CSS pixel the server should draw the geometry highlight at. */
+    async sendPixelScaleAsync(scale: number): Promise<void> {
+        await this.#sendWidgetTriggerAsync('set_pixel_scale', { scale });
+    }
 }
diff --git a/src/ansys/visor/visor-client/src/renderer/WasmRenderer.ts b/src/ansys/visor/visor-client/src/renderer/WasmRenderer.ts
index 4fbfdf65..620c37d7 100644
--- a/src/ansys/visor/visor-client/src/renderer/WasmRenderer.ts
+++ b/src/ansys/visor/visor-client/src/renderer/WasmRenderer.ts
@@ -165,6 +165,9 @@ export class WasmRenderer implements IRenderer {
     }
 
     async resizeAsync(): Promise<void> {
+        // Not awaited: the resize does not wait on a round trip, and the send
+        // logs and swallows its own rejection.
+        void this.#sends.sendPixelScaleAsync(window.devicePixelRatio);
         await this.#vtkScene.resizeAsync();
         await this.#orientationWidget.fitToWindowAsync();
         this.#vtkScene.render();
@@ -513,11 +516,13 @@ export class WasmRenderer implements IRenderer {
         return (await this.#vtkScene.pickGeometryAsync(normX, normY, mode)) as PickGeometryResult;
     }
 
+    /** Ask the server to highlight the picked feature; a not-found result clears it. */
     async setGeometryHighlightAsync(result: PickGeometryResult): Promise<void> {
-        await this.#vtkScene.setGeometryHighlightAsync(result);
+        await this.#sends.sendGeometryHighlightAsync(result);
     }
 
+    /** Ask the server to clear the highlight; the send is not awaited. */
     clearGeometryHighlight(): void {
-        this.#vtkScene.clearGeometryHighlight();
+        void this.#sends.sendGeometryHighlightAsync({ found: false });
     }
 }
diff --git a/src/ansys/visor/visor-client/src/wasm/VtkScene.js b/src/ansys/visor/visor-client/src/wasm/VtkScene.js
index dc1aa7a0..91cefb3f 100644
--- a/src/ansys/visor/visor-client/src/wasm/VtkScene.js
+++ b/src/ansys/visor/visor-client/src/wasm/VtkScene.js
@@ -73,7 +73,6 @@ export default class VtkScene {
         this.#setupFpsMonitor();
         this.#setupCamera();
         this.#setupPicker();
-        this.#setupHighlightOverlay();
     }
 
     /**@type{RemoteVtkScene}*/
@@ -225,125 +224,6 @@ export default class VtkScene {
         }
     };
 
-    // ── Client-side geometry highlight (Canvas 2D overlay) ──────────────────
-    /**@type{HTMLCanvasElement|null}*/
-    #highlightCanvas = null;
-    /**@type{any|null}*/
-    #highlightResult = null;
-
-    #setupHighlightOverlay = () => {
-        const overlay = document.createElement('canvas');
-        overlay.style.position = 'absolute';
-        overlay.style.top = '0';
-        overlay.style.left = '0';
-        overlay.style.pointerEvents = 'none';
-        this.canvasDiv.appendChild(overlay);
-        this.#highlightCanvas = overlay;
-        // Redraw when camera moves so the projected positions stay correct.
-        this.addCameraChangedListener(() => {
-            this.#drawHighlight().catch(() => {});
-        });
-    };
-
-    /**
-     * Project a world-space point to overlay canvas pixels (top-left origin).
-     * @param {number[]} worldPt  [x, y, z]
-     * @return {Promise<number[]>}  [canvasX, canvasY]
-     */
-    #projectWorldToCanvas = async (worldPt) => {
-        await this.renderer.SetWorldPoint(worldPt[0], worldPt[1], worldPt[2], 1.0);
-        await this.renderer.WorldToDisplay();
-        const dp = await this.renderer.GetDisplayPoint();
-        // dp: [x, y, z] — VTK display coords (x left→right, y bottom→top, in render-window pixels)
-        const winSize = await this.renderWindow.GetSize();
-        const normX = dp[0] / winSize[0];
-        const normY = dp[1] / winSize[1]; // 0 = bottom
-        const overlay = this.#highlightCanvas;
-        const canvasX = normX * overlay.width;
-        const canvasY = (1 - normY) * overlay.height; // flip Y for canvas2d
-        return [canvasX, canvasY];
-    };
-
-    #drawHighlight = async () => {
-        const canvas = this.#highlightCanvas;
-        if (!canvas) return;
-        // Match canvas size to its CSS display size
-        const rect = this.canvasDiv.getBoundingClientRect();
-        canvas.width = rect.width;
-        canvas.height = rect.height;
-        const ctx = canvas.getContext('2d');
-        ctx.clearRect(0, 0, canvas.width, canvas.height);
-
-        const result = this.#highlightResult;
-        if (!result || !result.found) return;
-
-        ctx.strokeStyle = 'rgba(255, 165, 0, 1)'; // orange
-        ctx.fillStyle = 'rgba(255, 165, 0, 0.35)';
-        ctx.lineWidth = 3;
-        ctx.lineJoin = 'round';
-        ctx.lineCap = 'round';
-
-        if (result.mode === 'vertex') {
-            // Project the exact snapped vertex world position to canvas.
-            const [cx, cy] = await this.#projectWorldToCanvas(result.position);
-            ctx.beginPath();
-            ctx.arc(cx, cy, 9, 0, 2 * Math.PI);
-            ctx.fill();
-            ctx.stroke();
-        } else if (result.mode === 'edge') {
-            const [ax, ay] = await this.#projectWorldToCanvas(result.pointA);
-            const [bx, by] = await this.#projectWorldToCanvas(result.pointB);
-            ctx.lineWidth = 4;
-            ctx.beginPath();
-            ctx.moveTo(ax, ay);
-            ctx.lineTo(bx, by);
-            ctx.stroke();
-            // endpoint dots
-            ctx.beginPath();
-            ctx.arc(ax, ay, 5, 0, 2 * Math.PI);
-            ctx.fill();
-            ctx.beginPath();
-            ctx.arc(bx, by, 5, 0, 2 * Math.PI);
-            ctx.fill();
-        } else if (result.mode === 'face' && result.points && result.points.length >= 3) {
-            const screenPts = [];
-            for (const p of result.points) {
-                screenPts.push(await this.#projectWorldToCanvas(p));
-            }
-            ctx.beginPath();
-            ctx.moveTo(screenPts[0][0], screenPts[0][1]);
-            for (let i = 1; i < screenPts.length; i++) {
-                ctx.lineTo(screenPts[i][0], screenPts[i][1]);
-            }
-            ctx.closePath();
-            ctx.fill();
-            ctx.stroke();
-        }
-    };
-
-    /**
-     * Draw a highlight overlay for a pick result returned by pickGeometryAsync.
-     * @param {any} result
-     * @return {Promise<void>}
-     */
-    setGeometryHighlightAsync = async (result) => {
-        this.#highlightResult = result;
-        await this.#drawHighlight();
-    };
-
-    /**
-     * Clear the geometry highlight overlay.
-     */
-    clearGeometryHighlight = () => {
-        this.#highlightResult = null;
-        const canvas = this.#highlightCanvas;
-        if (canvas) {
-            const ctx = canvas.getContext('2d');
-            ctx.clearRect(0, 0, canvas.width, canvas.height);
-        }
-    };
-    // ────────────────────────────────────────────────────────────────────────
-
     /**
      * @param {(fps:number)=>void} handler
      * @return {()=>void}
diff --git a/tests/unit/app/test_scene_trigger_app.py b/tests/unit/app/test_scene_trigger_app.py
index 78d6d22e..a10c3ee0 100644
--- a/tests/unit/app/test_scene_trigger_app.py
+++ b/tests/unit/app/test_scene_trigger_app.py
@@ -2,12 +2,14 @@
 
 Coverage targets
 ----------------
-1.  ``LocalApp`` registers exactly these 22 trigger names: the 19 shared ones
-    defined on ``SceneTriggerApp`` plus its own three local-only ones.
+1.  ``LocalApp`` registers exactly these 23 trigger names: the 19 shared ones
+    defined on ``SceneTriggerApp`` plus its own four local-only ones.
     Neither a missing nor a doubled registration passes this.
 2.  ``LocalApp`` seeds ``rendering_mode`` into server state as ``"client"``
     before the server starts.
 3.  ``set_geometry_highlight`` hands the coordinator the parsed pick.
+4.  ``set_pixel_scale`` hands the coordinator the parsed scale, and a scale
+    that is not positive never reaches it.
 
 The coordinator and payload behaviour of the other 18 shared triggers is
 already pinned, trigger by trigger, in ``test_local_app.py`` and its sibling
@@ -21,8 +23,8 @@
 from ansys.visor.viewer.app.trame.local_app import LocalApp
 from ansys.visor.viewer.models.runtime.picking.geometry_pick import EdgePick
 
-# The exact 22 trigger names LocalApp registers: the 19 names shared with
-# every rendering mode, plus LocalApp's own three local-only ones.  Written
+# The exact 23 trigger names LocalApp registers: the 19 names shared with
+# every rendering mode, plus LocalApp's own four local-only ones.  Written
 # out by hand, not derived from the production trigger list, so a missing or
 # a doubled registration fails this rather than following along.
 LOCAL_APP_TRIGGER_NAMES = sorted(
@@ -49,6 +51,7 @@
         "pick_geometry",
         "perf_report_wasm",
         "perf_report_server_update",
+        "set_pixel_scale",
     ]
 )
 
@@ -83,7 +86,7 @@ def mock_server():
 
 
 def test_local_app_registers_exactly_these_triggers(mock_server):
-    """The registered trigger names are exactly the hand-written 22, sorted.
+    """The registered trigger names are exactly the hand-written 23, sorted.
 
     A missing registration shortens the list; a doubled one (``@TrameApp()``
     on both the base and the leaf) duplicates a name in
@@ -138,3 +141,35 @@ def test_set_geometry_highlight_forwards_the_parsed_pick(mock_server):
     api.set_geometry_highlight.assert_called_once_with(
         EdgePick(point_a=[0.0, 0.0, 0.0], point_b=[3.0, 4.0, 0.0], length=5.0)
     )
+
+
+def test_set_pixel_scale_forwards_the_parsed_scale(mock_server):
+    """The client's device pixel ratio reaches the coordinator as the float it sent."""
+    api = MagicMock(name="scene_mutation_api")
+    app = LocalApp(
+        server=mock_server,
+        get_scene_details_json=MagicMock(),
+        standalone=True,
+        scene_mutation_api=api,
+    )
+
+    result = app.set_pixel_scale({"scale": 2.0})
+
+    assert result is None
+    api.set_pixel_scale.assert_called_once_with(2.0)
+
+
+@pytest.mark.parametrize("scale", [0.0, -1.0])
+def test_set_pixel_scale_ignores_a_scale_that_is_not_positive(mock_server, scale):
+    """A scale of zero or less would draw no highlight at all, so it never reaches the coordinator."""
+    api = MagicMock(name="scene_mutation_api")
+    app = LocalApp(
+        server=mock_server,
+        get_scene_details_json=MagicMock(),
+        standalone=True,
+        scene_mutation_api=api,
+    )
+
+    app.set_pixel_scale({"scale": scale})
+
+    api.set_pixel_scale.assert_not_called()
diff --git a/tests/unit/renderer/test_local_renderer.py b/tests/unit/renderer/test_local_renderer.py
index a0d97616..5caea119 100644
--- a/tests/unit/renderer/test_local_renderer.py
+++ b/tests/unit/renderer/test_local_renderer.py
@@ -1225,6 +1225,23 @@ def test_clear_of_a_hidden_highlight_pushes_nothing(self, renderer):
         renderer._local_view.update.assert_not_called()
 
 
+class TestHighlightPixelScale:
+    """The client's device pixel ratio sizes the highlight the next time it is shown."""
+
+    def test_a_vertex_highlight_after_set_pixel_scale_is_drawn_at_the_scaled_size(self, renderer):
+        renderer.set_pixel_scale(2.0)
+
+        renderer.show_geometry_highlight(VertexPick(position=[1.0, 2.0, 3.0]))
+
+        # 21 CSS px vertex diameter at 2 device pixels per CSS pixel.
+        assert renderer._geometry_highlight.actor.GetProperty().GetPointSize() == 42.0
+
+    def test_set_pixel_scale_pushes_nothing(self, renderer):
+        renderer.set_pixel_scale(2.0)
+
+        renderer._local_view.update.assert_not_called()
+
+
 
 class TestPickGeometry:
 
diff --git a/tests/unit/vtk/scene/test_local_scene.py b/tests/unit/vtk/scene/test_local_scene.py
index 5d07425b..4c680096 100644
--- a/tests/unit/vtk/scene/test_local_scene.py
+++ b/tests/unit/vtk/scene/test_local_scene.py
@@ -733,6 +733,20 @@ def recording_pick_geometry_in_view(view, x, y, mode):
     assert depths == [1]
 
 
+def test_set_pixel_scale_holds_the_lock_at_the_renderer_call(pipeline_instance):
+    """The renderer's rescale runs with the scene lock held, and passes the scale through."""
+    pipeline_instance._vtk_lock = LockSpy()
+    calls = []
+
+    def recording_set_pixel_scale(pixel_scale):
+        calls.append((pixel_scale, pipeline_instance._vtk_lock.depth))
+
+    pipeline_instance._renderer.set_pixel_scale = recording_set_pixel_scale
+    pipeline_instance.set_pixel_scale(2.0)
+    assert calls == [(2.0, 1)]
+    assert pipeline_instance._vtk_lock.depth == 0
+
+
 # ---------------------------------------------------------------------------
 # Tests moved from tests/unit/app/test_finalize_scene.py
 # ---------------------------------------------------------------------------

From c28dcbeac48a0e9baf6bf5c7da122abc52ac0dbf Mon Sep 17 00:00:00 2001
From: Laura Kasian <lkasian@synopsys.com>
Date: Mon, 2 Nov 2026 15:53:03 -0700
Subject: [PATCH 2/7] fix: remove render call from data only path

---
 src/ansys/visor/viewer/renderer/local_renderer.py | 8 ++++++--
 tests/unit/renderer/test_local_renderer.py        | 6 ++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/ansys/visor/viewer/renderer/local_renderer.py b/src/ansys/visor/viewer/renderer/local_renderer.py
index 6b3335cb..1f971900 100644
--- a/src/ansys/visor/viewer/renderer/local_renderer.py
+++ b/src/ansys/visor/viewer/renderer/local_renderer.py
@@ -309,12 +309,16 @@ def flush_wasm_state(self) -> None:
         self._local_view.update()
 
     def push_without_rebuild(self) -> None:
-        """Render, then push the whole render window to the wasm client as data only, so its frontend is not rebuilt.
+        """Push the whole render window to the wasm client as data only, so its frontend is not rebuilt; renders nothing.
 
         No object is named, so the window and everything it holds is sent,
         including an actor that has just become visible.
+
+        The window is not rendered: this runs on the trigger thread, while the
+        window's GL context is current on the thread that rendered it first
+        (the API caller's), and a context is current on one thread at a time.
+        Only serialisation is needed: the wasm client draws the pushed state.
         """
-        self._render_window.Render()
         self._local_view.update(**{DATA_ONLY_UPDATE_OPTION: True})
 
     @property
diff --git a/tests/unit/renderer/test_local_renderer.py b/tests/unit/renderer/test_local_renderer.py
index 5caea119..73faaa0c 100644
--- a/tests/unit/renderer/test_local_renderer.py
+++ b/tests/unit/renderer/test_local_renderer.py
@@ -1220,6 +1220,12 @@ def test_clear_of_a_visible_highlight_pushes_once_with_data_only(self, renderer)
 
         renderer._local_view.update.assert_called_once_with(dataOnly=True)
 
+    def test_set_does_not_render_the_window(self, renderer):
+        """The push runs on the trigger thread, which does not own the window's GL context."""
+        renderer.show_geometry_highlight(VertexPick(position=[1.0, 2.0, 3.0]))
+        renderer._render_window.Render.assert_not_called()
+        renderer._local_view.update.assert_called_once_with(dataOnly=True)
+
     def test_clear_of_a_hidden_highlight_pushes_nothing(self, renderer):
         renderer.show_geometry_highlight(NoGeometryPick())
         renderer._local_view.update.assert_not_called()

From 7f8b38fef5f5ff3300d3df5e1eef76d32b5dc0aa Mon Sep 17 00:00:00 2001
From: Laura Kasian <lkasian@synopsys.com>
Date: Tue, 3 Nov 2026 08:19:49 -0700
Subject: [PATCH 3/7] fix: guard against resizing a 0x0 wasm window in client
 mode

---
 .../src/jest-tests/CanvasPixelSize.test.ts    | 24 +++++++++++++++++++
 .../visor-client/src/wasm/CanvasPixelSize.ts  | 20 ++++++++++++++++
 .../visor-client/src/wasm/RemoteVtkScene.js   | 11 ++++++---
 3 files changed, 52 insertions(+), 3 deletions(-)
 create mode 100644 src/ansys/visor/visor-client/src/jest-tests/CanvasPixelSize.test.ts
 create mode 100644 src/ansys/visor/visor-client/src/wasm/CanvasPixelSize.ts

diff --git a/src/ansys/visor/visor-client/src/jest-tests/CanvasPixelSize.test.ts b/src/ansys/visor/visor-client/src/jest-tests/CanvasPixelSize.test.ts
new file mode 100644
index 00000000..e801cdcb
--- /dev/null
+++ b/src/ansys/visor/visor-client/src/jest-tests/CanvasPixelSize.test.ts
@@ -0,0 +1,24 @@
+import { CanvasPixelSize } from '../wasm/CanvasPixelSize';
+
+/**
+ * The wasm render window is sized from its container's CSS box at the
+ * device pixel ratio.  A box that rounds to 0 on either side gives no size,
+ * so the window keeps its last one: a 0-sized window is never set.
+ */
+
+describe('CanvasPixelSize.of', () => {
+    test('scales the CSS box by the pixel ratio and rounds to the nearest pixel', () => {
+        const size = CanvasPixelSize.of(400.3, 300.2, 2);
+        expect(size).not.toBeNull();
+        expect([size!.width, size!.height]).toEqual([801, 600]);
+    });
+
+    test.each([
+        ['a zero-sized box', 0, 0],
+        ['a zero width', 0, 300],
+        ['a zero height', 400, 0],
+        ['a box that rounds to zero', 0.2, 0.2],
+    ])('gives no size for %s', (_name, width, height) => {
+        expect(CanvasPixelSize.of(width, height, 1)).toBeNull();
+    });
+});
diff --git a/src/ansys/visor/visor-client/src/wasm/CanvasPixelSize.ts b/src/ansys/visor/visor-client/src/wasm/CanvasPixelSize.ts
new file mode 100644
index 00000000..00e08d8b
--- /dev/null
+++ b/src/ansys/visor/visor-client/src/wasm/CanvasPixelSize.ts
@@ -0,0 +1,20 @@
+/** A render-window size in device pixels, never 0 on either side. */
+export class CanvasPixelSize {
+    /** The device-pixel size of a CSS box at a pixel ratio, or null when either side rounds to 0. */
+    static of(cssWidth: number, cssHeight: number, pixelRatio: number): CanvasPixelSize | null {
+        const width = Math.floor(cssWidth * pixelRatio + 0.5);
+        const height = Math.floor(cssHeight * pixelRatio + 0.5);
+        if (width <= 0 || height <= 0) {
+            return null;
+        }
+        return new CanvasPixelSize(width, height);
+    }
+
+    private constructor(width: number, height: number) {
+        this.width = width;
+        this.height = height;
+    }
+
+    readonly width: number;
+    readonly height: number;
+}
diff --git a/src/ansys/visor/visor-client/src/wasm/RemoteVtkScene.js b/src/ansys/visor/visor-client/src/wasm/RemoteVtkScene.js
index a5e817aa..50cda156 100644
--- a/src/ansys/visor/visor-client/src/wasm/RemoteVtkScene.js
+++ b/src/ansys/visor/visor-client/src/wasm/RemoteVtkScene.js
@@ -1,4 +1,5 @@
 import { VtkWASMHandler } from '@kitware/vtk-wasm/remote';
+import { CanvasPixelSize } from './CanvasPixelSize';
 import { SerialUpdateQueue } from './SerialUpdateQueue';
 import TrameInterface from './TrameInterface.js';
 import VtkScene from './VtkScene.js';
@@ -312,13 +313,17 @@ export default class RemoteVtkScene {
         return this.#wasmHandler.sceneManager.render(this.renderWindowId);
     };
     /**
+     * Size the wasm window to its container; a container with no area, as before it is placed or while it is
+     * between frontends, leaves the window at its last size.
      * @return {Promise<void>}
      */
     resizeAsync = async () => {
         const { width, height } = this.canvasDiv.getBoundingClientRect();
-        const w = Math.floor(width * window.devicePixelRatio + 0.5);
-        const h = Math.floor(height * window.devicePixelRatio + 0.5);
-        await this.#wasmHandler.setSize(this.renderWindowId, w, h);
+        const size = CanvasPixelSize.of(width, height, window.devicePixelRatio);
+        if (size === null) {
+            return;
+        }
+        await this.#wasmHandler.setSize(this.renderWindowId, size.width, size.height);
     };
     /**
      * @param {number} wasmId

From f2f6084e54e68332e0a32dcaddaf9372e2664482 Mon Sep 17 00:00:00 2001
From: pyansys-ci-bot <92810346+pyansys-ci-bot@users.noreply.github.com>
Date: Tue, 3 Nov 2026 16:57:53 +0000
Subject: [PATCH 4/7] chore: adding changelog file 204.added.md
 [dependabot-skip]

---
 doc/changelog.d/204.added.md | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 doc/changelog.d/204.added.md

diff --git a/doc/changelog.d/204.added.md b/doc/changelog.d/204.added.md
new file mode 100644
index 00000000..c2bc9d9f
--- /dev/null
+++ b/doc/changelog.d/204.added.md
@@ -0,0 +1 @@
+Pick and highlight geometry through the server in client mode

From a34332b177b2939cf1fc3dbec1a3470ad321dc6d Mon Sep 17 00:00:00 2001
From: Laura Kasian <lkasian@synopsys.com>
Date: Tue, 3 Nov 2026 12:41:27 -0700
Subject: [PATCH 5/7] feat: pick and highlight geometry through the server in
 client mode

---
 src/ansys/visor/viewer/app/trame/local_app.py |  33 ++--
 src/ansys/visor/viewer/app/visor_vtk_local.py |   8 +-
 .../requests/geometry_pick_payloads.py        |  16 +-
 .../visor/viewer/renderer/local_renderer.py   |  68 --------
 .../visor/viewer/vtk/scene/local_scene.py     |  11 +-
 .../visor-client/src/CameraSyncReporter.ts    |  59 ++++---
 .../WasmRendererWidgetTriggers.test.tsx       |  59 +++++++
 .../visor-client/src/renderer/WasmRenderer.ts |  18 +-
 .../visor/visor-client/src/wasm/VtkScene.js   |  50 ------
 tests/integration/test_visor_local_scene.py   |  65 -------
 tests/unit/app/test_local_app.py              |   2 +
 .../unit/app/test_local_app_set_projection.py |   2 +
 tests/unit/app/test_local_app_sync_camera.py  |   2 +
 ...test_local_app_sync_cross_section_plane.py |   1 +
 .../app/test_local_app_ui_panel_triggers.py   |   1 +
 .../app/test_local_app_widget_triggers.py     |   2 +
 tests/unit/app/test_scene_trigger_app.py      |  86 +++++++++-
 tests/unit/app/test_visor_trame_app.py        |   8 +
 tests/unit/app/test_visor_vtk_local.py        |  12 +-
 tests/unit/renderer/test_local_renderer.py    | 162 +-----------------
 .../vtk/picking/test_cell_feature_finder.py   | 109 ++++++++++++
 21 files changed, 369 insertions(+), 405 deletions(-)
 create mode 100644 tests/unit/vtk/picking/test_cell_feature_finder.py

diff --git a/src/ansys/visor/viewer/app/trame/local_app.py b/src/ansys/visor/viewer/app/trame/local_app.py
index 1d727a0c..f28f4b0d 100644
--- a/src/ansys/visor/viewer/app/trame/local_app.py
+++ b/src/ansys/visor/viewer/app/trame/local_app.py
@@ -1,5 +1,5 @@
 from logging import Logger
-from typing import Protocol
+from typing import Callable, Protocol
 
 from trame.app.core import Server
 from trame.decorators import TrameApp, trigger
@@ -13,7 +13,10 @@
 from ansys.visor.viewer.config import settings
 from ansys.visor.viewer.core.visor_enums import RenderingMode
 from ansys.visor.viewer.core.visor_logging import VisorDefaultLogger
+from ansys.visor.viewer.models.runtime.picking.geometry_pick import GeometryPick
+from ansys.visor.viewer.models.runtime.requests.geometry_pick_payloads import PickGeometryInViewPayload
 from ansys.visor.viewer.models.runtime.requests.pixel_scale_payload import SetPixelScalePayload
+from ansys.visor.viewer.vtk.picking.part_cell_hit import PickView
 
 logger = VisorDefaultLogger(__name__)
 
@@ -31,13 +34,14 @@ def set_pixel_scale(self, pixel_scale: float) -> None: ...
 class LocalApp(SceneTriggerApp):
     """
     LocalApp serves the scene triggers shared by every rendering mode, plus
-    the local-only triggers for sub-geometry picking and client performance
-    reporting, for client-side rendering via VTK-WASM in the browser.
+    the local-only triggers for sub-geometry picking through the client's
+    view and client performance reporting, for client-side rendering via
+    VTK-WASM in the browser.
 
     Attributes:
         server (Server): the Trame server instance
     Methods:
-        pick_geometry: picks the geometry for rendering
+        pick_geometry_in_view: picks the geometry feature under a pixel of the client's window
         perf_report_wasm: reports the performance of the wasm update cycle
         perf_report_server_update: reports the performance of the server update cycle
         set_pixel_scale: sets the device pixel ratio the geometry highlight is drawn at
@@ -49,11 +53,11 @@ def __init__(
             get_scene_details_json: callable,
             standalone: bool = True,
             trame_logger: Logger | None = None,
-            pick_geometry=None,
             scene_mutation_api: LocalSceneMutationApi | None = None,
+            *,
+            pick_geometry_in_view: Callable[[PickView, int, int, str], GeometryPick],
     ):
-        # Callable for sub-geometry picking (optional), local-only.
-        self._pick_geometry = pick_geometry
+        self._pick_geometry_in_view = pick_geometry_in_view
         super().__init__(
             server=server,
             get_scene_details_json=get_scene_details_json,
@@ -67,12 +71,15 @@ def rendering_mode(self) -> RenderingMode:
         """This app serves client-side rendering via VTK-WASM in the browser."""
         return RenderingMode.CLIENT
 
-    @trigger("pick_geometry")
-    def pick_geometry(self, actor_wasm_id, cell_id, mode: str, world_x: float, world_y: float, world_z: float):
-        """Frontend → Backend: perform sub-geometry picking given a WASM actor/cell ID and world-space point."""
-        if self._pick_geometry is None:
-            return {"found": False}
-        return self._pick_geometry(actor_wasm_id, cell_id, mode, world_x, world_y, world_z)
+    @trigger("pick_geometry_in_view")
+    @parse_payload(PickGeometryInViewPayload)
+    def pick_geometry_in_view(self, payload) -> dict:
+        """Frontend -> Backend: the geometry feature under a pixel of the client's window, dumped by alias.
+
+        Picked through the client's camera and window size; highlights nothing.
+        """
+        view = PickView(camera_state=payload.camera, width=payload.width, height=payload.height)
+        return self._pick_geometry_in_view(view, payload.x, payload.y, payload.mode).model_dump(by_alias=True)
 
     @trigger("set_pixel_scale")
     @parse_payload(SetPixelScalePayload)
diff --git a/src/ansys/visor/viewer/app/visor_vtk_local.py b/src/ansys/visor/viewer/app/visor_vtk_local.py
index 690734b2..77b730ff 100644
--- a/src/ansys/visor/viewer/app/visor_vtk_local.py
+++ b/src/ansys/visor/viewer/app/visor_vtk_local.py
@@ -44,17 +44,11 @@ def _initialize_rendering(self, standalone: bool, trame_log_dir: str | None) ->
             lambda: self._scene.get_scene_details_json(),
             standalone,
             trame_logger=get_trame_logger(trame_log_dir),
-            pick_geometry=lambda
-                actor_wasm_id,
-                cell_id,
-                mode,
-                world_x,
-                world_y,
-                world_z: self._scene.pick_geometry(actor_wasm_id, cell_id, mode, world_x, world_y, world_z),
             # The scene satisfies LocalApp's LocalSceneMutationApi protocol
             # structurally: the coordinator methods carry exactly the names
             # and signatures the triggers call.
             scene_mutation_api=self._scene,
+            pick_geometry_in_view=self._scene.pick_geometry_in_view,
         )
 
     def _post_scene_change_hook(self) -> None:
diff --git a/src/ansys/visor/viewer/models/runtime/requests/geometry_pick_payloads.py b/src/ansys/visor/viewer/models/runtime/requests/geometry_pick_payloads.py
index 673a47df..de52f7a4 100644
--- a/src/ansys/visor/viewer/models/runtime/requests/geometry_pick_payloads.py
+++ b/src/ansys/visor/viewer/models/runtime/requests/geometry_pick_payloads.py
@@ -1,7 +1,10 @@
 """Models for the geometry-pick trigger payloads."""
 
-from pydantic import BaseModel
+from typing import Annotated
 
+from pydantic import BaseModel, Field
+
+from ansys.visor.viewer.models.common.visor_camera_state import VisorCameraState
 from ansys.visor.viewer.models.runtime.picking.geometry_pick import GeometryPick, GeometryPickMode
 
 
@@ -13,6 +16,17 @@ class PickGeometryAtPayload(BaseModel):
     mode: GeometryPickMode
 
 
+class PickGeometryInViewPayload(BaseModel):
+    """pick_geometry_in_view payload: a pixel of the client's window, origin bottom-left, the window's size, its camera record, and the mode."""
+
+    x: int
+    y: int
+    width: Annotated[int, Field(gt=0)]
+    height: Annotated[int, Field(gt=0)]
+    mode: GeometryPickMode
+    camera: VisorCameraState
+
+
 class SetGeometryHighlightPayload(BaseModel):
     """set_geometry_highlight payload: the pick whose feature to highlight; a not-found pick clears it."""
 
diff --git a/src/ansys/visor/viewer/renderer/local_renderer.py b/src/ansys/visor/viewer/renderer/local_renderer.py
index 1f971900..0a35c175 100644
--- a/src/ansys/visor/viewer/renderer/local_renderer.py
+++ b/src/ansys/visor/viewer/renderer/local_renderer.py
@@ -23,14 +23,12 @@
 from ansys.visor.viewer.core.perf_timer import PerfTimer
 from ansys.visor.viewer.core.visor_colors import VisorColors
 from ansys.visor.viewer.core.visor_logging import VisorDefaultLogger
-from ansys.visor.viewer.models.runtime.picking.geometry_pick import NoGeometryPick
 from ansys.visor.viewer.models.runtime.vtk.renderer_annotation import (
     WasmNodeHandles,
     WasmRendererAnnotation,
     WasmWidgetHandles,
 )
 from ansys.visor.viewer.renderer.pipeline_renderer import VtkPipelineRenderer
-from ansys.visor.viewer.vtk.picking.cell_feature_finder import CellFeatureFinder
 from ansys.visor.viewer.vtk.widgets.visor_bounding_box import VisorBoundingBox
 from ansys.visor.viewer.vtk.widgets.visor_cross_section import VisorCrossSectionWidget
 from ansys.visor.viewer.vtk.widgets.visor_orientation import VisorOrientationWidget
@@ -217,72 +215,6 @@ def set_cross_section_visibility(self, visible: bool) -> None:
     def set_bounding_box_visibility(self, visible: bool) -> None:
         """No-op: the widget's enablement is driven client-side."""
 
-    # ------------------------------------------------------------------
-    # Local-only: picking
-    # ------------------------------------------------------------------
-
-    def pick_geometry(
-        self,
-        actor_wasm_id: int,
-        cell_id: int,
-        mode: str,
-        world_pos: tuple[float, float, float],
-    ) -> dict:
-        """
-        Resolve a client-initiated pick event to a sub-geometry payload.
-
-        The actor is found by matching each renderer actor's object-manager
-        id against *actor_wasm_id*; the coordinator never performs that
-        resolution.
-
-        Parameters
-        ----------
-        actor_wasm_id:
-            Client-supplied opaque actor identifier from the wasm-side picker.
-        cell_id:
-            Cell index within the picked actor's mapper dataset.
-        mode:
-            ``"vertex" | "edge" | "face"``.
-        world_pos:
-            World-space pick position from the client picker, used to select
-            the nearest vertex/edge for multi-vertex/edge cells.
-
-        Returns
-        -------
-        dict
-            Backend-neutral pick result. Always contains ``"found": bool``.
-            When ``found`` is ``True``, contains ``"mode"`` and mode-specific
-            fields (``position`` / ``pointA``+``pointB``+``edgeLength`` /
-            ``points``+``area``).
-        """
-        actor_wasm_id = int(actor_wasm_id)
-        cell_id = int(cell_id)
-        pick_pos = (float(world_pos[0]), float(world_pos[1]), float(world_pos[2]))
-
-        if actor_wasm_id < 0 or cell_id < 0:
-            return NoGeometryPick().model_dump(by_alias=True)
-
-        # Locate the actor by iterating the renderer's actors and matching
-        # WASM IDs (avoids depending on a GetObjectAtId reverse-lookup API).
-        actor = None
-        actors = self._vtk_renderer.GetActors()
-        actors.InitTraversal()
-        a = actors.GetNextActor()
-        while a is not None:
-            if self._object_manager.GetId(a) == actor_wasm_id:
-                actor = a
-                break
-            a = actors.GetNextActor()
-
-        if actor is None:
-            return NoGeometryPick().model_dump(by_alias=True)
-
-        finder = CellFeatureFinder.from_dataset(
-            actor.GetMapper().GetInputDataObject(0, 0), cell_id, pick_pos
-        )
-        pick = finder.find(mode) if finder is not None else NoGeometryPick()
-        return pick.model_dump(by_alias=True)
-
     # ------------------------------------------------------------------
     # IRenderer: render
     # ------------------------------------------------------------------
diff --git a/src/ansys/visor/viewer/vtk/scene/local_scene.py b/src/ansys/visor/viewer/vtk/scene/local_scene.py
index 654659dd..60c71344 100644
--- a/src/ansys/visor/viewer/vtk/scene/local_scene.py
+++ b/src/ansys/visor/viewer/vtk/scene/local_scene.py
@@ -66,18 +66,9 @@ def _push_runtime_state(self, runtime_app_state: "RuntimeAppState") -> None:
         self._frontend_bridge.set_state(runtime_app_state)
 
     # -------------------------------------------------------------------------
-    # Picking — wasm: the client's picker reports a wasm actor id
+    # Picking — through the client's view, on the server picker
     # -------------------------------------------------------------------------
 
-    def pick_geometry(self, actor_wasm_id, cell_id, mode, world_x, world_y, world_z) -> dict:
-        """
-        Frontend-trigger entry point for cell picking.  Packs the world-space
-        pick position into a tuple and delegates to the renderer backend.
-        """
-        return self._renderer.pick_geometry(
-            actor_wasm_id, cell_id, mode, (world_x, world_y, world_z)
-        )
-
     def set_pixel_scale(self, pixel_scale: float) -> None:
         """Draw the geometry highlight at this many device pixels per CSS pixel; no push, no notify.
 
diff --git a/src/ansys/visor/visor-client/src/CameraSyncReporter.ts b/src/ansys/visor/visor-client/src/CameraSyncReporter.ts
index 51b02b1b..7c3139ac 100644
--- a/src/ansys/visor/visor-client/src/CameraSyncReporter.ts
+++ b/src/ansys/visor/visor-client/src/CameraSyncReporter.ts
@@ -16,18 +16,21 @@ import type { WasmRenderer } from './renderer/WasmRenderer';
  * event is what the debounce exists to avoid.
  */
 
+/** The seven camera fields the server applies and picks through. Mirrors the server's camera model. */
+export type CameraRecord = Readonly<{
+    position: readonly number[];
+    focalPoint: readonly number[];
+    viewUp: readonly number[];
+    clippingRange: readonly number[];
+    parallelProjection: boolean;
+    viewAngle: number;
+    parallelScale: number;
+}>;
+
 /** The payload of the `sync_camera` trigger. Mirrors the server's model. */
 export type SyncCameraPayload = Readonly<{
     origin: CameraOrigin;
-    camera: Readonly<{
-        position: readonly number[];
-        focalPoint: readonly number[];
-        viewUp: readonly number[];
-        clippingRange: readonly number[];
-        parallelProjection: boolean;
-        viewAngle: number;
-        parallelScale: number;
-    }>;
+    camera: CameraRecord;
 }>;
 
 /**
@@ -42,7 +45,7 @@ export type CameraSyncSource = Pick<
 >;
 
 /**
- * Build the trigger payload from a settled camera snapshot.
+ * The server's camera record from a camera snapshot.
  *
  * The seven applied fields are named one by one, deliberately, rather than
  * spread from the snapshot. `VisorCameraState` carries five further derived
@@ -52,13 +55,30 @@ export type CameraSyncSource = Pick<
  * accept it silently: pydantic ignores unknown keys, so every server-side
  * gate would stay green while the wire contract quietly became "whatever the
  * client's snapshot type happens to hold today". Naming the seven is the only
- * place that shape is decided, which is why the test asserts the key set.
+ * place that shape is decided, which is why the tests assert the key set.
  *
  * `parallelProjection` is carried verbatim. `getCameraStateAsync` has already
- * narrowed the wasm camera's raw value to a boolean; this module does not
+ * narrowed the wasm camera's raw value to a boolean; this function does not
  * re-derive it.
+ */
+export function cameraRecordOf(camera: VisorCameraState): CameraRecord {
+    return {
+        position: camera.position,
+        focalPoint: camera.focalPoint,
+        viewUp: camera.viewUp,
+        clippingRange: camera.clippingRange,
+        parallelProjection: camera.parallelProjection,
+        viewAngle: camera.viewAngle,
+        parallelScale: camera.parallelScale,
+    };
+}
+
+/**
+ * Build the trigger payload from a settled camera snapshot.
  *
- * `origin` is carried verbatim too, for both values. The client never
+ * The camera is the record `cameraRecordOf` names, never the snapshot.
+ *
+ * `origin` is carried verbatim, for both values. The client never
  * suppresses a report it believes is an echo -- the server decides, and logs
  * what it dropped.
  */
@@ -66,18 +86,7 @@ export function buildSyncCameraPayload(
     origin: CameraOrigin,
     camera: VisorCameraState
 ): SyncCameraPayload {
-    return {
-        origin,
-        camera: {
-            position: camera.position,
-            focalPoint: camera.focalPoint,
-            viewUp: camera.viewUp,
-            clippingRange: camera.clippingRange,
-            parallelProjection: camera.parallelProjection,
-            viewAngle: camera.viewAngle,
-            parallelScale: camera.parallelScale,
-        },
-    };
+    return { origin, camera: cameraRecordOf(camera) };
 }
 
 /**
diff --git a/src/ansys/visor/visor-client/src/jest-tests/WasmRendererWidgetTriggers.test.tsx b/src/ansys/visor/visor-client/src/jest-tests/WasmRendererWidgetTriggers.test.tsx
index 142fd96a..71d7db39 100644
--- a/src/ansys/visor/visor-client/src/jest-tests/WasmRendererWidgetTriggers.test.tsx
+++ b/src/ansys/visor/visor-client/src/jest-tests/WasmRendererWidgetTriggers.test.tsx
@@ -39,6 +39,10 @@ import type { TrameTriggerSender } from '../renderer/IRenderer';
  * `set_geometry_highlight` with the pick, so the server draws and drops it;
  * the scene no longer draws one of its own.
  *
+ * Also pinned: a geometry pick sends `pick_geometry_in_view` once, with the
+ * clicked pixel of the window in render-window pixels, the window's size and
+ * the camera record, so the server picks through the view the user sees.
+ *
  * Modelled on `WasmRendererPartTriggers.test.tsx`, which does the same for
  * the six per-part sends.
  */
@@ -135,8 +139,18 @@ async function makeRenderer(
     nodeIds: number[] = [NODE_ID]
 ) {
     const objects = makeFakeWasmObjects();
+    // The six camera reads besides the projection return distinctive
+    // hand-written literals, none a vtkCamera default, so a record carrying
+    // them can only have come from reading this camera.
     const camera = {
         GetParallelProjection: jest.fn(async () => parallelProjection),
+        GetParallelScale: jest.fn(async () => 7),
+        GetDistance: jest.fn(async () => 9),
+        GetPosition: jest.fn(async () => [1, 2, 3]),
+        GetFocalPoint: jest.fn(async () => [4, 5, 6]),
+        GetViewUp: jest.fn(async () => [0, 0, 1]),
+        GetClippingRange: jest.fn(async () => [0.5, 50]),
+        GetViewAngle: jest.fn(async () => 25),
         ParallelProjectionOn: jest.fn(async () => undefined),
         ParallelProjectionOff: jest.fn(async () => undefined),
     };
@@ -150,6 +164,7 @@ async function makeRenderer(
         renderWindow: {
             GetSize: jest.fn(async () => windowSize),
         },
+        getViewPortHeightAsync: jest.fn(async () => windowSize[1]),
         clearObserversAndEventListeners: jest.fn(),
         // The tracker itself is `#private` to VtkScene, so what the renderer
         // can reach is this one passthrough, and this is what the orientation
@@ -478,3 +493,47 @@ describe('WasmRenderer geometry highlight sends', () => {
         ]);
     });
 });
+
+describe('WasmRenderer geometry pick', () => {
+    // (0.25, 0.25) on 600x400 is pixel (150, 100). A y flip would give 300,
+    // an x flip 450, and swapped axes (100, 150).
+    test('pickGeometryAsync sends one pick_geometry_in_view with the window pixel, its size and the camera record', async () => {
+        const sender = jest.fn(async () => ({ found: false })) as unknown as jest.Mock &
+            TrameTriggerSender;
+        const { renderer, scene } = await makeRenderer(sender);
+        scene.renderWindow.GetSize.mockResolvedValue([600, 400]);
+
+        const result = await renderer.pickGeometryAsync(0.25, 0.25, 'vertex');
+
+        expect(result).toStrictEqual({ found: false });
+        expect(sender.mock.calls).toStrictEqual([
+            [
+                'pick_geometry_in_view',
+                {
+                    x: 150,
+                    y: 100,
+                    width: 600,
+                    height: 400,
+                    mode: 'vertex',
+                    camera: {
+                        position: [1, 2, 3],
+                        focalPoint: [4, 5, 6],
+                        viewUp: [0, 0, 1],
+                        clippingRange: [0.5, 50],
+                        parallelProjection: false,
+                        viewAngle: 25,
+                        parallelScale: 7,
+                    },
+                },
+            ],
+        ]);
+    });
+
+    test('pickGeometryAsync with no trigger sender rejects', async () => {
+        const { renderer } = await makeRenderer(null);
+
+        await expect(renderer.pickGeometryAsync(0.25, 0.25, 'vertex')).rejects.toThrow(
+            'no trigger sender'
+        );
+    });
+});
diff --git a/src/ansys/visor/visor-client/src/renderer/WasmRenderer.ts b/src/ansys/visor/visor-client/src/renderer/WasmRenderer.ts
index 620c37d7..030349fb 100644
--- a/src/ansys/visor/visor-client/src/renderer/WasmRenderer.ts
+++ b/src/ansys/visor/visor-client/src/renderer/WasmRenderer.ts
@@ -16,6 +16,9 @@ import { OrthographicWidget } from '../widgets/orthographicWidget.ts';
 import { EdgesWidget } from '../widgets/edgesWidget.ts';
 import { OrientationWidget } from '../widgets/orientationWidget.ts';
 import { SceneTriggerSends } from './SceneTriggerSends';
+import { ViewportPixel } from '../input/ViewportPixel';
+import { GeometryPickReader } from './GeometryPickReader';
+import { cameraRecordOf } from '../CameraSyncReporter';
 
 const SELECTION_TINT_RGB: Readonly<number[]> = [0 / 255, 62 / 255, 111 / 255];
 
@@ -32,6 +35,7 @@ export class WasmRenderer implements IRenderer {
         triggerSender: TrameTriggerSender | null
     ) {
         this.#vtkScene = vtkScene;
+        this.#triggerSender = triggerSender;
         this.#sends = new SceneTriggerSends(triggerSender);
 
         const wasmPlaneId = annotation.widgets.crossSectionPlaneId;
@@ -148,6 +152,7 @@ export class WasmRenderer implements IRenderer {
     }
 
     readonly #vtkScene: VtkScene;
+    readonly #triggerSender: TrameTriggerSender | null;
     readonly #sends: SceneTriggerSends;
     readonly #actorIdToNodeId = new Map<number, NodeId>();
     readonly #nodeIdToHandles = new Map<NodeId, WasmNodeHandles>();
@@ -508,12 +513,23 @@ export class WasmRenderer implements IRenderer {
     }
 
     // ---- Picking ------------------------------------------------------------
+    /** Ask the server for the feature under a point of this window, seen through its camera, in render-window pixels; rejects with no trigger sender. */
     async pickGeometryAsync(
         normX: number,
         normY: number,
         mode: GeometryPickMode
     ): Promise<PickGeometryResult> {
-        return (await this.#vtkScene.pickGeometryAsync(normX, normY, mode)) as PickGeometryResult;
+        const send = this.#triggerSender;
+        if (send == null) {
+            throw new Error('no trigger sender');
+        }
+        const [width, height] = await this.#vtkScene.renderWindow.GetSize();
+        const x = ViewportPixel.of(normX, width);
+        const y = ViewportPixel.of(normY, height);
+        const camera = cameraRecordOf(await this.getCameraStateAsync());
+        return GeometryPickReader.parse(
+            await send('pick_geometry_in_view', { x, y, width, height, mode, camera })
+        );
     }
 
     /** Ask the server to highlight the picked feature; a not-found result clears it. */
diff --git a/src/ansys/visor/visor-client/src/wasm/VtkScene.js b/src/ansys/visor/visor-client/src/wasm/VtkScene.js
index 91cefb3f..b5a96b54 100644
--- a/src/ansys/visor/visor-client/src/wasm/VtkScene.js
+++ b/src/ansys/visor/visor-client/src/wasm/VtkScene.js
@@ -81,8 +81,6 @@ export default class VtkScene {
     canvas;
     /**@type{HTMLDivElement}*/
     canvasDiv;
-    /** Last WASM display coords from mouseup – used by pickGeometryAsync. */
-    #lastPickDisplayPos = null;
     /**@type{FrontendVtkObject}*/
     camera;
     /**@type{FrontendVtkObject}*/
@@ -177,53 +175,6 @@ export default class VtkScene {
     addViewerClickedListener = (handler) => {
         return this.#viewerClicks.addListener(handler);
     };
-    /**
-     * Pick geometry at the last clicked position.
-     *
-     * The interactor's picker is a vtkCellPicker (set server-side), which
-     * returns the exact hit cell via GetCellId().  The actor's WASM object ID
-     * is retrieved from the actor proxy.  Both are forwarded to the server so
-     * it can look up the cell vertices directly
-     *
-     * @param {number} normX - Normalized x [0..1] (kept for API compatibility)
-     * @param {number} normY - Normalized y [0..1] bottom→top (VTK convention)
-     * @param {string} mode  - 'vertex' | 'edge' | 'face'
-     * @return {Promise<{found:boolean, mode?:string, position?:number[], pointA?:number[], pointB?:number[], edgeLength?:number, area?:number, points?:number[][]}>}
-     */
-    pickGeometryAsync = async (normX, normY, mode) => {
-        const displayPos = this.#lastPickDisplayPos;
-        if (!displayPos) return { found: false };
-        const [dx, dy] = displayPos;
-
-        // Re-pick at the exact WASM display coordinates.
-        const found = await this.picker.Pick([dx, dy, 0], this.renderer);
-        if (!found) return { found: false };
-
-        const rawPos = await this.picker.GetPickPosition();
-        const position = [rawPos[0], rawPos[1], rawPos[2]];
-
-        // For all modes (vertex, edge, face): use vtkCellPicker's exact cell ID
-        // and actor WASM ID so the server can snap to the nearest vertex / edge / face.
-        try {
-            const cellId = await this.picker.GetCellId();
-            if (cellId < 0) return { found: false };
-            const actorProxy = await this.picker.GetActor();
-            const actorWasmId = actorProxy?.id ?? null;
-            if (actorWasmId == null) return { found: false };
-            return await this.#remoteVtkScene.trameTriggerAsync(
-                'pick_geometry',
-                actorWasmId,
-                cellId,
-                mode,
-                position[0],
-                position[1],
-                position[2]
-            );
-        } catch (_) {
-            return { found: false };
-        }
-    };
-
     /**
      * @param {(fps:number)=>void} handler
      * @return {()=>void}
@@ -272,7 +223,6 @@ export default class VtkScene {
                 };
                 await this.#viewerClicks.dispatchAsync(click, async () => {
                     const [x, y] = await interactor.GetEventPosition();
-                    this.#lastPickDisplayPos = [x, y];
                     const found = await picker.Pick([x, y, 0], renderer);
                     const actor = found ? await picker.getActor() : null;
                     return actor?.id ?? null;
diff --git a/tests/integration/test_visor_local_scene.py b/tests/integration/test_visor_local_scene.py
index 3c481488..61b34f58 100644
--- a/tests/integration/test_visor_local_scene.py
+++ b/tests/integration/test_visor_local_scene.py
@@ -1,7 +1,6 @@
 # python
 # File: `tests/integration/test_visor_local_scene.py`
 import json
-import math
 import os
 from unittest.mock import PropertyMock, patch
 
@@ -190,67 +189,3 @@ def test_list_and_update_variables(pipeline_instance):
     assert part.variables[0].name == "Normal"
     assert part.variables[0].type == VisorVtkVariableType.POINT
     assert part.variables[0].num_components == num_components
-
-
-def test_pick_geometry(pipeline_instance):
-    """Test that pick_geometry works."""
-    file = get_test_file()
-    dataset = file_to_dataset(file)
-    metadata = ExtendedMetadata(name="pick_test", unit="m")
-    dataset_id = pipeline_instance.add_dataset(dataset, metadata)
-    pipeline_instance.populate_scene()
-    # ensure VTK pipeline has produced outputs
-    pipeline_instance.render()
-
-    dataset_node = pipeline_instance._scene_graph.get_descendant_node(dataset_id)
-    assert dataset_node is not None
-    actors = [
-        pipeline_instance._renderer._pipelines[part.id].actor
-        for part in dataset_node.get_descendant_part_nodes(include_self=True)
-        if part.id in pipeline_instance._renderer._pipelines
-    ]
-    assert len(actors) > 0
-    # choose an actor whose mapper input dataset contains cells
-    actor = None
-    for a in actors:
-        try:
-            ds = a.GetMapper().GetInputDataObject(0, 0)
-            if ds is not None and ds.GetNumberOfCells() > 0:
-                actor = a
-                pick_ds = ds
-                break
-        except Exception:
-            continue
-    assert actor is not None
-    actor_wasm_id = pipeline_instance._renderer._object_manager.GetId(actor)
-
-    # Test face pick for first cell
-    res_face = pipeline_instance.pick_geometry(actor_wasm_id, 0, 'face', 0.0, 0.0, 0.0)
-    assert res_face["found"] is True
-    assert res_face["mode"] == "face"
-    assert "area" in res_face and res_face["area"] > 0
-    assert len(res_face["points"]) >= 3
-
-    # Test vertex pick using the first point of cell 0
-    # Use the mapper's dataset for cell/point selection
-    cell = pick_ds.GetCell(0)
-    pts = cell.GetPoints()
-    p0 = pts.GetPoint(0)
-    res_vertex = pipeline_instance.pick_geometry(actor_wasm_id, 0, 'vertex', p0[0], p0[1], p0[2])
-    assert res_vertex["found"] is True
-    assert res_vertex["mode"] == "vertex"
-    assert tuple(res_vertex["position"]) == tuple(p0)
-
-    # Test edge pick for first edge (p0 -> p1) using midpoint
-    if cell.GetNumberOfPoints() >= 2:
-        p1 = pts.GetPoint(1)
-        mid = ((p0[0] + p1[0]) / 2.0, (p0[1] + p1[1]) / 2.0, (p0[2] + p1[2]) / 2.0)
-        res_edge = pipeline_instance.pick_geometry(actor_wasm_id, 0, 'edge', mid[0], mid[1], mid[2])
-        assert res_edge["found"] is True
-        assert res_edge["mode"] == "edge"
-        assert tuple(res_edge["pointA"]) == tuple(p0)
-        assert tuple(res_edge["pointB"]) == tuple(p1)
-        assert math.isclose(res_edge["edgeLength"], math.dist(p0, p1))
-    else:
-        pytest.skip("not enough points for edge pick test")
-
diff --git a/tests/unit/app/test_local_app.py b/tests/unit/app/test_local_app.py
index 27eefc02..b09d5214 100644
--- a/tests/unit/app/test_local_app.py
+++ b/tests/unit/app/test_local_app.py
@@ -110,6 +110,7 @@ def app(mock_server, api):
         get_scene_details_json=MagicMock(),
         standalone=True,
         scene_mutation_api=api,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
@@ -120,6 +121,7 @@ def app_without_api(mock_server):
         server=mock_server,
         get_scene_details_json=MagicMock(),
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
diff --git a/tests/unit/app/test_local_app_set_projection.py b/tests/unit/app/test_local_app_set_projection.py
index bf2af6b2..3e7a8e1b 100644
--- a/tests/unit/app/test_local_app_set_projection.py
+++ b/tests/unit/app/test_local_app_set_projection.py
@@ -84,6 +84,7 @@ def app(mock_server, api):
         get_scene_details_json=MagicMock(),
         standalone=True,
         scene_mutation_api=api,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
@@ -94,6 +95,7 @@ def app_without_api(mock_server):
         server=mock_server,
         get_scene_details_json=MagicMock(),
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
diff --git a/tests/unit/app/test_local_app_sync_camera.py b/tests/unit/app/test_local_app_sync_camera.py
index 61c8868d..e35c63ec 100644
--- a/tests/unit/app/test_local_app_sync_camera.py
+++ b/tests/unit/app/test_local_app_sync_camera.py
@@ -103,6 +103,7 @@ def app(mock_server, api):
         get_scene_details_json=MagicMock(),
         standalone=True,
         scene_mutation_api=api,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
@@ -113,6 +114,7 @@ def app_without_api(mock_server):
         server=mock_server,
         get_scene_details_json=MagicMock(),
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
diff --git a/tests/unit/app/test_local_app_sync_cross_section_plane.py b/tests/unit/app/test_local_app_sync_cross_section_plane.py
index 38cfd2bc..9b137d89 100644
--- a/tests/unit/app/test_local_app_sync_cross_section_plane.py
+++ b/tests/unit/app/test_local_app_sync_cross_section_plane.py
@@ -80,6 +80,7 @@ def app(mock_server, api):
         get_scene_details_json=MagicMock(),
         standalone=True,
         scene_mutation_api=api,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
diff --git a/tests/unit/app/test_local_app_ui_panel_triggers.py b/tests/unit/app/test_local_app_ui_panel_triggers.py
index 55b5e0e9..b2f00731 100644
--- a/tests/unit/app/test_local_app_ui_panel_triggers.py
+++ b/tests/unit/app/test_local_app_ui_panel_triggers.py
@@ -85,6 +85,7 @@ def app(mock_server, api):
         get_scene_details_json=MagicMock(),
         standalone=True,
         scene_mutation_api=api,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
diff --git a/tests/unit/app/test_local_app_widget_triggers.py b/tests/unit/app/test_local_app_widget_triggers.py
index 07fffb1d..4dbb1ce7 100644
--- a/tests/unit/app/test_local_app_widget_triggers.py
+++ b/tests/unit/app/test_local_app_widget_triggers.py
@@ -80,6 +80,7 @@ def app(mock_server, api):
         get_scene_details_json=MagicMock(),
         standalone=True,
         scene_mutation_api=api,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
@@ -90,6 +91,7 @@ def app_without_api(mock_server):
         server=mock_server,
         get_scene_details_json=MagicMock(),
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
 
 
diff --git a/tests/unit/app/test_scene_trigger_app.py b/tests/unit/app/test_scene_trigger_app.py
index a10c3ee0..67fe3338 100644
--- a/tests/unit/app/test_scene_trigger_app.py
+++ b/tests/unit/app/test_scene_trigger_app.py
@@ -10,6 +10,9 @@
 3.  ``set_geometry_highlight`` hands the coordinator the parsed pick.
 4.  ``set_pixel_scale`` hands the coordinator the parsed scale, and a scale
     that is not positive never reaches it.
+5.  ``pick_geometry_in_view`` hands the server picker the client's pixel,
+    window size, camera and mode, and returns its pick dumped by alias; a
+    window with no width never reaches the picker.
 
 The coordinator and payload behaviour of the other 18 shared triggers is
 already pinned, trigger by trigger, in ``test_local_app.py`` and its sibling
@@ -21,7 +24,9 @@
 import pytest
 
 from ansys.visor.viewer.app.trame.local_app import LocalApp
+from ansys.visor.viewer.models.common.visor_camera_state import VisorCameraState
 from ansys.visor.viewer.models.runtime.picking.geometry_pick import EdgePick
+from ansys.visor.viewer.vtk.picking.part_cell_hit import PickView
 
 # The exact 23 trigger names LocalApp registers: the 19 names shared with
 # every rendering mode, plus LocalApp's own four local-only ones.  Written
@@ -48,7 +53,7 @@
         "set_panel_top_right_legend_collapsed",
         "set_panel_top_right_tab_index",
         "set_geometry_highlight",
-        "pick_geometry",
+        "pick_geometry_in_view",
         "perf_report_wasm",
         "perf_report_server_update",
         "set_pixel_scale",
@@ -97,6 +102,7 @@ def test_local_app_registers_exactly_these_triggers(mock_server):
         server=mock_server,
         get_scene_details_json=MagicMock(),
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
 
     names = sorted(call.args[0] for call in mock_server.trigger.call_args_list)
@@ -110,6 +116,7 @@ def test_local_app_seeds_rendering_mode_client(mock_server):
         server=mock_server,
         get_scene_details_json=MagicMock(),
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
 
     assert mock_server.state["rendering_mode"] == "client"
@@ -123,6 +130,7 @@ def test_set_geometry_highlight_forwards_the_parsed_pick(mock_server):
         get_scene_details_json=MagicMock(),
         standalone=True,
         scene_mutation_api=api,
+        pick_geometry_in_view=MagicMock(),
     )
 
     result = app.set_geometry_highlight(
@@ -151,6 +159,7 @@ def test_set_pixel_scale_forwards_the_parsed_scale(mock_server):
         get_scene_details_json=MagicMock(),
         standalone=True,
         scene_mutation_api=api,
+        pick_geometry_in_view=MagicMock(),
     )
 
     result = app.set_pixel_scale({"scale": 2.0})
@@ -168,8 +177,83 @@ def test_set_pixel_scale_ignores_a_scale_that_is_not_positive(mock_server, scale
         get_scene_details_json=MagicMock(),
         standalone=True,
         scene_mutation_api=api,
+        pick_geometry_in_view=MagicMock(),
     )
 
     app.set_pixel_scale({"scale": scale})
 
     api.set_pixel_scale.assert_not_called()
+
+
+# The camera record and the window, as the client sends them for a pick.
+_PICK_CAMERA = {
+    "position": [1.0, 2.0, 3.0],
+    "focalPoint": [4.0, 5.0, 6.0],
+    "viewUp": [0.0, 0.0, 1.0],
+    "clippingRange": [0.5, 50.0],
+    "parallelProjection": False,
+    "viewAngle": 25.0,
+    "parallelScale": 7.0,
+}
+
+
+def test_pick_geometry_in_view_forwards_a_pick_view_and_dumps_by_alias(mock_server):
+    """The client's pixel, window size, camera and mode reach the server picker; its pick returns keyed by alias."""
+    picker = MagicMock(
+        name="pick_geometry_in_view",
+        return_value=EdgePick(point_a=[0.0, 0.0, 0.0], point_b=[3.0, 4.0, 0.0], length=5.0),
+    )
+    app = LocalApp(
+        server=mock_server,
+        get_scene_details_json=MagicMock(),
+        standalone=True,
+        pick_geometry_in_view=picker,
+    )
+
+    result = app.pick_geometry_in_view(
+        {"x": 150, "y": 100, "width": 600, "height": 400, "mode": "edge", "camera": _PICK_CAMERA}
+    )
+
+    picker.assert_called_once_with(
+        PickView(
+            camera_state=VisorCameraState(
+                position=[1.0, 2.0, 3.0],
+                focal_point=[4.0, 5.0, 6.0],
+                view_up=[0.0, 0.0, 1.0],
+                clipping_range=[0.5, 50.0],
+                parallel_projection=False,
+                view_angle=25.0,
+                parallel_scale=7.0,
+            ),
+            width=600,
+            height=400,
+        ),
+        150,
+        100,
+        "edge",
+    )
+    assert result == {
+        "found": True,
+        "mode": "edge",
+        "pointA": [0.0, 0.0, 0.0],
+        "pointB": [3.0, 4.0, 0.0],
+        "edgeLength": 5.0,
+    }
+
+
+def test_pick_geometry_in_view_rejects_a_zero_width(mock_server):
+    """A window with no width has no pixel to pick, so the server picker is never asked."""
+    picker = MagicMock(name="pick_geometry_in_view")
+    app = LocalApp(
+        server=mock_server,
+        get_scene_details_json=MagicMock(),
+        standalone=True,
+        pick_geometry_in_view=picker,
+    )
+
+    result = app.pick_geometry_in_view(
+        {"x": 0, "y": 0, "width": 0, "height": 400, "mode": "vertex", "camera": _PICK_CAMERA}
+    )
+
+    assert result is None
+    picker.assert_not_called()
diff --git a/tests/unit/app/test_visor_trame_app.py b/tests/unit/app/test_visor_trame_app.py
index 99f5a84e..ff0e4e94 100644
--- a/tests/unit/app/test_visor_trame_app.py
+++ b/tests/unit/app/test_visor_trame_app.py
@@ -56,6 +56,7 @@ def test_init_sets_attributes(
         get_scene_details_json=mock_get_scene_details_json,
         standalone=True,
         trame_logger=mock_logger,
+        pick_geometry_in_view=MagicMock(),
     )
     assert app.server == mock_server
     assert app._get_scene_details_json == mock_get_scene_details_json
@@ -70,6 +71,7 @@ def test_register_lifecycle_hooks_adds_handlers(
         server=mock_server,
         get_scene_details_json=mock_get_scene_details_json,
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
     assert mock_server.controller.add_call_count >= 5
 
@@ -82,6 +84,7 @@ def test_set_headers_sets_http_headers(
         server=mock_server,
         get_scene_details_json=mock_get_scene_details_json,
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
     mock_server.http_headers.set_header.assert_any_call(
         "Access-Control-Allow-Origin", "*"
@@ -103,6 +106,7 @@ def test_set_www_path_sets_www(
         server=mock_server,
         get_scene_details_json=mock_get_scene_details_json,
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
     assert mock_server._www == "/mock/path"
 
@@ -115,6 +119,7 @@ def test_get_visor_scene_details_json_returns_scene_details(
         server=mock_server,
         get_scene_details_json=mock_get_scene_details_json,
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
     result = app.get_visor_scene_details_json()
     assert result == {"scene": "details"}
@@ -134,6 +139,7 @@ def test_trame_logger_is_set_when_provided(
         get_scene_details_json=mock_get_scene_details_json,
         standalone=True,
         trame_logger=mock_logger,
+        pick_geometry_in_view=MagicMock(),
     )
     assert app._SceneTriggerApp__trame_logger == mock_logger
 
@@ -150,6 +156,7 @@ def test_trame_logger_is_none_when_not_provided(
         server=mock_server,
         get_scene_details_json=mock_get_scene_details_json,
         standalone=True,
+        pick_geometry_in_view=MagicMock(),
     )
     assert app._SceneTriggerApp__trame_logger is None
 
@@ -168,6 +175,7 @@ def test_lifecycle_logging_calls_debug(
         get_scene_details_json=mock_get_scene_details_json,
         standalone=True,
         trame_logger=mock_logger,
+        pick_geometry_in_view=MagicMock(),
     )
 
     # Trigger each lifecycle event
diff --git a/tests/unit/app/test_visor_vtk_local.py b/tests/unit/app/test_visor_vtk_local.py
index e73e8706..4350929a 100644
--- a/tests/unit/app/test_visor_vtk_local.py
+++ b/tests/unit/app/test_visor_vtk_local.py
@@ -673,6 +673,13 @@ def test_local_app_receives_the_scene_as_the_scene_mutation_api(local_app_call):
     assert call.kwargs["scene_mutation_api"] is instance._scene
 
 
+def test_local_app_receives_the_scene_pick_geometry_in_view(local_app_call):
+    """The scene's own server picker is injected, not a lambda around it."""
+    call, scene, _instance = local_app_call
+
+    assert call.kwargs["pick_geometry_in_view"] is scene.pick_geometry_in_view
+
+
 def test_local_app_still_receives_the_pre_existing_arguments(local_app_call):
     """The boundary is extended, not broken: the earlier arguments survive."""
     call, scene, instance = local_app_call
@@ -681,20 +688,17 @@ def test_local_app_still_receives_the_pre_existing_arguments(local_app_call):
     assert server is instance.server
     assert callable(get_scene_details_json)
     assert standalone is True
-    assert callable(call.kwargs["pick_geometry"])
     assert "trame_logger" in call.kwargs
 
 
 def test_the_pre_existing_lambdas_still_delegate_to_the_scene(local_app_call):
-    """The two original callables are untouched and still reach the scene."""
+    """The original callable is untouched and still reaches the scene."""
     call, scene, _instance = local_app_call
 
     _server, get_scene_details_json, _standalone = call.args
     get_scene_details_json()
-    call.kwargs["pick_geometry"](2, 3, "vertex", 0.0, 1.0, 2.0)
 
     scene.get_scene_details_json.assert_called_once_with()
-    scene.pick_geometry.assert_called_once_with(2, 3, "vertex", 0.0, 1.0, 2.0)
 
 
 @pytest.mark.parametrize("name", SCENE_MUTATION_API_METHODS)
diff --git a/tests/unit/renderer/test_local_renderer.py b/tests/unit/renderer/test_local_renderer.py
index 73faaa0c..3ce48138 100644
--- a/tests/unit/renderer/test_local_renderer.py
+++ b/tests/unit/renderer/test_local_renderer.py
@@ -15,8 +15,7 @@
 4.  Camera -- reset_camera, sync_camera / get_camera_state, set_projection,
     each re-serializing the active camera without notifying the client.
 5.  Render / flush delegation.
-6.  pick_geometry -- vertex, edge, face modes.
-7.  Cross-section plane -- the record, the two VTK writes, the two-id
+6.  Cross-section plane -- the record, the two VTK writes, the two-id
     re-serialization, and the seed.
 """
 
@@ -38,75 +37,6 @@
 from ansys.visor.viewer.vtk.node_pipeline import VtkNodePipeline
 from ansys.visor.viewer.vtk.widgets.visor_cross_section import VisorCrossSectionWidget
 
-# ---------------------------------------------------------------------------
-# Lightweight VTK-data stubs (no real VTK objects required for pick tests)
-# ---------------------------------------------------------------------------
-
-class _DummyPoints:
-    def __init__(self, pts):
-        self._pts = pts
-
-    def GetPoint(self, i): # noqa: N802
-        return tuple(self._pts[i])
-
-
-class _DummyCell:
-    def __init__(self, points):
-        self._pts = _DummyPoints(points)
-        self._n = len(points)
-
-    def GetNumberOfPoints(self): # noqa: N802
-        return self._n
-
-    def GetPoints(self): # noqa: N802
-        return self._pts
-
-
-class _DummyDataset:
-    def __init__(self, cells):
-        self._cells = cells
-
-    def GetNumberOfCells(self): # noqa: N802
-        return len(self._cells)
-
-    def GetCell(self, idx): # noqa: N802
-        return self._cells[idx] if 0 <= idx < len(self._cells) else None
-
-
-class _DummyMapper:
-    def __init__(self, dataset):
-        self._ds = dataset
-
-    def GetInputDataObject(self, a, b): # noqa: N802
-        return self._ds
-
-
-class _DummyActor:
-    def __init__(self, mapper):
-        self._mapper = mapper
-
-    def GetMapper(self): # noqa: N802
-        return self._mapper
-
-
-class _DummyActors:
-    """Minimal traversable actor collection matching vtkActorCollection's API."""
-
-    def __init__(self, actors):
-        self._actors = actors
-        self._idx = 0
-
-    def InitTraversal(self): # noqa: N802
-        self._idx = 0
-
-    def GetNextActor(self): # noqa: N802
-        if self._idx >= len(self._actors):
-            return None
-        a = self._actors[self._idx]
-        self._idx += 1
-        return a
-
-
 # ---------------------------------------------------------------------------
 # Camera double
 #
@@ -291,23 +221,6 @@ def renderer():
     return r
 
 
-# ---------------------------------------------------------------------------
-# Helper: seed one actor into the renderer's actor list for pick tests
-# ---------------------------------------------------------------------------
-
-def _seed_actor(renderer, actor_wasm_id: int, dataset):
-    """Wire a dummy actor+dataset into the renderer's VTK actor traversal.
-
-    Returns the actor so callers can make additional assertions.
-    """
-    actor = _DummyActor(_DummyMapper(dataset))
-    renderer._vtk_renderer.GetActors.return_value = _DummyActors([actor])
-    renderer._object_manager.GetId.side_effect = (
-        lambda a: actor_wasm_id if a is actor else -1
-    )
-    return actor
-
-
 # ===========================================================================
 # 1.  Interface conformance
 # ===========================================================================
@@ -1249,79 +1162,8 @@ def test_set_pixel_scale_pushes_nothing(self, renderer):
 
 
 
-class TestPickGeometry:
-
-    def test_pick_vertex_returns_nearest_point(self, renderer):
-        """Vertex mode returns the cell point closest to the pick position."""
-        pts = [(0, 0, 0), (1, 0, 0), (0, 1, 0)]
-        dataset = _DummyDataset([_DummyCell(pts)])
-        _seed_actor(renderer, 123, dataset)
-
-        res = renderer.pick_geometry(123, 0, "vertex", (0.9, 0.1, 0.0))
-
-        assert res["found"] is True
-        assert res["mode"] == "vertex"
-        assert tuple(res["position"]) == (1.0, 0.0, 0.0)
-
-    def test_pick_edge_returns_closest_edge_endpoints_and_length(self, renderer):
-        """Edge mode returns the two endpoints of the edge nearest to the pick."""
-        pts = [(0, 0, 0), (2, 0, 0), (2, 2, 0), (0, 2, 0)]
-        dataset = _DummyDataset([_DummyCell(pts)])
-        _seed_actor(renderer, 7, dataset)
-
-        res = renderer.pick_geometry(7, 0, "edge", (2.01, 1.0, 0.0))
-
-        assert res["found"] is True
-        assert res["mode"] == "edge"
-        assert tuple(res["pointA"]) == (2.0, 0.0, 0.0)
-        assert tuple(res["pointB"]) == (2.0, 2.0, 0.0)
-        assert pytest.approx(res["edgeLength"]) == 2.0
-
-    def test_pick_face_returns_area_and_all_points(self, renderer):
-        """Face mode returns the polygon area and every cell point."""
-        pts = [(0, 0, 0), (1, 0, 0), (1, 2, 0), (0, 2, 0)]
-        dataset = _DummyDataset([_DummyCell(pts)])
-        _seed_actor(renderer, 5, dataset)
-
-        res = renderer.pick_geometry(5, 0, "face", (0.5, 1.0, 0.0))
-
-        assert res["found"] is True
-        assert res["mode"] == "face"
-        assert pytest.approx(res["area"]) == 2.0
-        assert len(res["points"]) == 4
-
-    def test_pick_negative_actor_id_returns_not_found(self, renderer):
-        res = renderer.pick_geometry(-1, 0, "vertex", (0.0, 0.0, 0.0))
-        assert res == {"found": False}
-
-    def test_pick_negative_cell_id_returns_not_found(self, renderer):
-        res = renderer.pick_geometry(1, -1, "vertex", (0.0, 0.0, 0.0))
-        assert res == {"found": False}
-
-    def test_pick_unregistered_actor_returns_not_found(self, renderer):
-        """If no actor matches the given wasm id, pick returns not-found."""
-        renderer._vtk_renderer.GetActors.return_value = _DummyActors([])
-        res = renderer.pick_geometry(42, 0, "vertex", (0.0, 0.0, 0.0))
-        assert res["found"] is False
-
-    def test_pick_cell_id_out_of_range_returns_not_found(self, renderer):
-        """Cell index beyond dataset size returns not-found."""
-        dataset = _DummyDataset([_DummyCell([(0, 0, 0), (1, 0, 0), (0, 1, 0)])])
-        _seed_actor(renderer, 10, dataset)
-        res = renderer.pick_geometry(10, 99, "vertex", (0.0, 0.0, 0.0))
-        assert res["found"] is False
-
-    def test_pick_unknown_mode_returns_not_found(self, renderer):
-        """An unrecognised mode string falls through to not-found."""
-        pts = [(0, 0, 0), (1, 0, 0), (0, 1, 0)]
-        dataset = _DummyDataset([_DummyCell(pts)])
-        _seed_actor(renderer, 1, dataset)
-        res = renderer.pick_geometry(1, 0, "INVALID_MODE", (0.0, 0.0, 0.0))
-        assert res == {"found": False}
-
-
 # ===========================================================================
-# 7.  The cross-section plane record
+# 6.  The cross-section plane record
 #
 # Hand-written widget double rather than a MagicMock, on the precedent
 # ``_CameraDouble`` sets in this module: the seed reads ``GetOrigin`` and
diff --git a/tests/unit/vtk/picking/test_cell_feature_finder.py b/tests/unit/vtk/picking/test_cell_feature_finder.py
new file mode 100644
index 00000000..503b18bb
--- /dev/null
+++ b/tests/unit/vtk/picking/test_cell_feature_finder.py
@@ -0,0 +1,109 @@
+"""
+Unit tests for CellFeatureFinder.
+
+Coverage targets
+----------------
+1.  find -- vertex, edge and face modes, dumped by alias as the wire carries
+    them; an unknown mode is not found.
+2.  from_dataset -- a negative cell id, a cell id past the last cell, and no
+    dataset at all each give no finder.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from ansys.visor.viewer.vtk.picking.cell_feature_finder import CellFeatureFinder
+
+# ---------------------------------------------------------------------------
+# Lightweight VTK-data stubs (no real VTK objects required)
+# ---------------------------------------------------------------------------
+
+class _DummyPoints:
+    def __init__(self, pts):
+        self._pts = pts
+
+    def GetPoint(self, i): # noqa: N802
+        return tuple(self._pts[i])
+
+
+class _DummyCell:
+    def __init__(self, points):
+        self._pts = _DummyPoints(points)
+        self._n = len(points)
+
+    def GetNumberOfPoints(self): # noqa: N802
+        return self._n
+
+    def GetPoints(self): # noqa: N802
+        return self._pts
+
+
+class _DummyDataset:
+    def __init__(self, cells):
+        self._cells = cells
+
+    def GetNumberOfCells(self): # noqa: N802
+        return len(self._cells)
+
+    def GetCell(self, idx): # noqa: N802
+        return self._cells[idx] if 0 <= idx < len(self._cells) else None
+
+
+class TestCellFeatureFinder:
+
+    def test_vertex_returns_nearest_point(self):
+        """Vertex mode returns the cell point closest to the pick position."""
+        pts = [(0, 0, 0), (1, 0, 0), (0, 1, 0)]
+        dataset = _DummyDataset([_DummyCell(pts)])
+
+        res = CellFeatureFinder.from_dataset(dataset, 0, (0.9, 0.1, 0.0)).find("vertex").model_dump(by_alias=True)
+
+        assert res["found"] is True
+        assert res["mode"] == "vertex"
+        assert tuple(res["position"]) == (1.0, 0.0, 0.0)
+
+    def test_edge_returns_closest_edge_endpoints_and_length(self):
+        """Edge mode returns the two endpoints of the edge nearest to the pick."""
+        pts = [(0, 0, 0), (2, 0, 0), (2, 2, 0), (0, 2, 0)]
+        dataset = _DummyDataset([_DummyCell(pts)])
+
+        res = CellFeatureFinder.from_dataset(dataset, 0, (2.01, 1.0, 0.0)).find("edge").model_dump(by_alias=True)
+
+        assert res["found"] is True
+        assert res["mode"] == "edge"
+        assert tuple(res["pointA"]) == (2.0, 0.0, 0.0)
+        assert tuple(res["pointB"]) == (2.0, 2.0, 0.0)
+        assert pytest.approx(res["edgeLength"]) == 2.0
+
+    def test_face_returns_area_and_all_points(self):
+        """Face mode returns the polygon area and every cell point."""
+        pts = [(0, 0, 0), (1, 0, 0), (1, 2, 0), (0, 2, 0)]
+        dataset = _DummyDataset([_DummyCell(pts)])
+
+        res = CellFeatureFinder.from_dataset(dataset, 0, (0.5, 1.0, 0.0)).find("face").model_dump(by_alias=True)
+
+        assert res["found"] is True
+        assert res["mode"] == "face"
+        assert pytest.approx(res["area"]) == 2.0
+        assert len(res["points"]) == 4
+
+    def test_negative_cell_id_is_not_found(self):
+        dataset = _DummyDataset([_DummyCell([(0, 0, 0), (1, 0, 0), (0, 1, 0)])])
+        assert CellFeatureFinder.from_dataset(dataset, -1, (0.0, 0.0, 0.0)) is None
+
+    def test_cell_id_out_of_range_is_not_found(self):
+        """Cell index beyond dataset size gives no finder."""
+        dataset = _DummyDataset([_DummyCell([(0, 0, 0), (1, 0, 0), (0, 1, 0)])])
+        assert CellFeatureFinder.from_dataset(dataset, 99, (0.0, 0.0, 0.0)) is None
+
+    def test_unknown_mode_returns_not_found(self):
+        """An unrecognised mode string falls through to not-found."""
+        pts = [(0, 0, 0), (1, 0, 0), (0, 1, 0)]
+        dataset = _DummyDataset([_DummyCell(pts)])
+        res = CellFeatureFinder.from_dataset(dataset, 0, (0.0, 0.0, 0.0)).find("INVALID_MODE").model_dump(by_alias=True)
+        assert res == {"found": False}
+
+    def test_none_dataset_is_not_found(self):
+        """A picked actor whose mapper has no input dataset gives no finder."""
+        assert CellFeatureFinder.from_dataset(None, 0, (0.0, 0.0, 0.0)) is None

From e19cecaa50e1f6d5e7c713a457995f67ae111ff9 Mon Sep 17 00:00:00 2001
From: Laura Kasian <lkasian@synopsys.com>
Date: Tue, 3 Nov 2026 13:46:23 -0700
Subject: [PATCH 6/7] chore: skip resizing the wasm window when canvas size has
 not changed

---
 .../src/jest-tests/CanvasPixelSize.test.ts            | 10 ++++++++++
 .../visor/visor-client/src/wasm/CanvasPixelSize.ts    |  5 +++++
 .../visor/visor-client/src/wasm/RemoteVtkScene.js     | 11 +++++++++--
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/ansys/visor/visor-client/src/jest-tests/CanvasPixelSize.test.ts b/src/ansys/visor/visor-client/src/jest-tests/CanvasPixelSize.test.ts
index e801cdcb..c3a06aa7 100644
--- a/src/ansys/visor/visor-client/src/jest-tests/CanvasPixelSize.test.ts
+++ b/src/ansys/visor/visor-client/src/jest-tests/CanvasPixelSize.test.ts
@@ -22,3 +22,13 @@ describe('CanvasPixelSize.of', () => {
         expect(CanvasPixelSize.of(width, height, 1)).toBeNull();
     });
 });
+
+describe('CanvasPixelSize.equals', () => {
+    test('is true for the same size and false for a different width, height or null', () => {
+        const size = CanvasPixelSize.of(400, 300, 1)!;
+        expect(size.equals(CanvasPixelSize.of(400, 300, 1))).toBe(true);
+        expect(size.equals(CanvasPixelSize.of(401, 300, 1))).toBe(false);
+        expect(size.equals(CanvasPixelSize.of(400, 301, 1))).toBe(false);
+        expect(size.equals(null)).toBe(false);
+    });
+});
diff --git a/src/ansys/visor/visor-client/src/wasm/CanvasPixelSize.ts b/src/ansys/visor/visor-client/src/wasm/CanvasPixelSize.ts
index 00e08d8b..93756948 100644
--- a/src/ansys/visor/visor-client/src/wasm/CanvasPixelSize.ts
+++ b/src/ansys/visor/visor-client/src/wasm/CanvasPixelSize.ts
@@ -15,6 +15,11 @@ export class CanvasPixelSize {
         this.height = height;
     }
 
+    /** Whether other is the same device-pixel size; false for null. */
+    equals(other: CanvasPixelSize | null): boolean {
+        return other !== null && other.width === this.width && other.height === this.height;
+    }
+
     readonly width: number;
     readonly height: number;
 }
diff --git a/src/ansys/visor/visor-client/src/wasm/RemoteVtkScene.js b/src/ansys/visor/visor-client/src/wasm/RemoteVtkScene.js
index 50cda156..f36b5821 100644
--- a/src/ansys/visor/visor-client/src/wasm/RemoteVtkScene.js
+++ b/src/ansys/visor/visor-client/src/wasm/RemoteVtkScene.js
@@ -314,17 +314,24 @@ export default class RemoteVtkScene {
     };
     /**
      * Size the wasm window to its container; a container with no area, as before it is placed or while it is
-     * between frontends, leaves the window at its last size.
+     * between frontends, leaves the window at its last size.  A size equal to the one last applied is not set
+     * again: vtk-wasm's `setSize` renders, and its `update` already re-applies the last size it was given.
      * @return {Promise<void>}
      */
     resizeAsync = async () => {
         const { width, height } = this.canvasDiv.getBoundingClientRect();
         const size = CanvasPixelSize.of(width, height, window.devicePixelRatio);
-        if (size === null) {
+        if (size === null || size.equals(this.#appliedSize)) {
             return;
         }
         await this.#wasmHandler.setSize(this.renderWindowId, size.width, size.height);
+        this.#appliedSize = size;
     };
+    /**
+     * The size last handed to vtk-wasm's `setSize`, recorded once it resolves; null until the first.
+     * @type {?CanvasPixelSize}
+     */
+    #appliedSize = null;
     /**
      * @param {number} wasmId
      * @return {FrontendVtkObject}

From 53b5e220e5f8195bd849a673bbc2adad7c8d7444 Mon Sep 17 00:00:00 2001
From: Laura Kasian <lkasian@synopsys.com>
Date: Wed, 4 Nov 2026 09:36:29 -0700
Subject: [PATCH 7/7] fix: read the picked actor with invoke instead of a
 property read

---
 src/ansys/visor/visor-client/src/wasm/VtkScene.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ansys/visor/visor-client/src/wasm/VtkScene.js b/src/ansys/visor/visor-client/src/wasm/VtkScene.js
index b5a96b54..77315671 100644
--- a/src/ansys/visor/visor-client/src/wasm/VtkScene.js
+++ b/src/ansys/visor/visor-client/src/wasm/VtkScene.js
@@ -224,7 +224,7 @@ export default class VtkScene {
                 await this.#viewerClicks.dispatchAsync(click, async () => {
                     const [x, y] = await interactor.GetEventPosition();
                     const found = await picker.Pick([x, y, 0], renderer);
-                    const actor = found ? await picker.getActor() : null;
+                    const actor = found ? await picker.GetActor() : null;
                     return actor?.id ?? null;
                 });
             } finally {