docs(webxr): add webxr example

Author: munozco

README.rst

@@ -121,6 +121,7 @@ The vtkRenderWindow is only used to retrieve the scene data and parameters (colo
 By relying on the same vtkRenderWindow, you can easily switch from a `VtkRemoteView` to a `VtkLocalView` or vice-versa.
 This component gives you controls on how you want to map mouse interaction with the camera.
 The default setting mimic default VTK interactor style so you will rarely have to override to the `interactor_settings`.
+The VtkLocalView supports WebXR thanks to the `VtkWebXRHelper` component. Please refer to the examples for details on how to use it.
 
 How to use it?
 ```````````````````````````````````````````````````````````

examples/vue3/cone-webxr.py

@@ -0,0 +1,111 @@
+from trame.app import get_server
+from trame.widgets import vuetify3, vtk as vtk_widgets
+from trame.ui.vuetify3 import SinglePageLayout
+
+from vtkmodules.vtkFiltersSources import vtkConeSource
+from vtkmodules.vtkRenderingCore import (
+    vtkRenderer,
+    vtkRenderWindow,
+    vtkRenderWindowInteractor,
+    vtkPolyDataMapper,
+    vtkActor,
+)
+
+# VTK factory initialization
+from vtkmodules.vtkInteractionStyle import vtkInteractorStyleSwitch  # noqa
+import vtkmodules.vtkRenderingOpenGL2  # noqa
+
+# -----------------------------------------------------------------------------
+# Trame initialization
+# -----------------------------------------------------------------------------
+
+server = get_server()
+server.client_type = "vue3"
+state, ctrl = server.state, server.controller
+
+state.trame__title = "VTK Local rendering"
+state.xr_active = False
+
+DEFAULT_RESOLUTION = 6
+
+# -----------------------------------------------------------------------------
+# VTK code
+# -----------------------------------------------------------------------------
+
+renderer = vtkRenderer()
+renderer.SetBackground(0.0231, 0.4194, 0.5592)
+renderWindow = vtkRenderWindow()
+renderWindow.AddRenderer(renderer)
+renderWindow.OffScreenRenderingOn()  # Prevent popup window
+
+renderWindowInteractor = vtkRenderWindowInteractor()
+renderWindowInteractor.SetRenderWindow(renderWindow)
+renderWindowInteractor.GetInteractorStyle().SetCurrentStyleToTrackballCamera()
+
+cone_source = vtkConeSource()
+mapper = vtkPolyDataMapper()
+actor = vtkActor()
+mapper.SetInputConnection(cone_source.GetOutputPort())
+actor.SetMapper(mapper)
+renderer.AddActor(actor)
+renderer.ResetCamera()
+renderWindow.Render()
+
+
+@state.change("resolution")
+def update_cone(resolution=DEFAULT_RESOLUTION, **kwargs):
+    cone_source.SetResolution(resolution)
+    ctrl.view_update()
+
+
+def update_reset_resolution():
+    state.resolution = DEFAULT_RESOLUTION
+
+
+def toggle_xr():
+    if state.xr_active:
+        ctrl.stop_xr()
+    else:
+        ctrl.start_xr(vtk_widgets.VtkWebXRHelper.XrSessionTypes.HmdVR)
+
+
+with SinglePageLayout(server) as layout:
+    layout.title.set_text("WebXR Cone")
+
+    with layout.toolbar:
+        vuetify3.VSpacer()
+        vuetify3.VSlider(
+            density="compact",
+            v_model=("resolution", DEFAULT_RESOLUTION),
+            min=3,
+            max=60,
+            step=1,
+            hide_details=True,
+            dense=True,
+            style="max-width: 300px",
+        )
+        vuetify3.VDivider(vertical=True, classes="mx-2")
+        with vuetify3.VBtn(icon=True, click=toggle_xr):
+            vuetify3.VIcon("mdi-virtual-reality")
+
+    with layout.content:
+        with vuetify3.VContainer(
+            fluid=True,
+            classes="pa-0 fill-height",
+        ):
+            with vtk_widgets.VtkLocalView(renderWindow) as view:
+                ctrl.view_update = view.update
+
+                def on_enter_xr():
+                    state.xr_active = True
+
+                def on_exit_xr():
+                    state.xr_active = False
+
+                webxr_helper = vtk_widgets.VtkWebXRHelper(
+                    draw_controllers_ray=True, enter_xr=on_enter_xr, exit_xr=on_exit_xr
+                )
+                ctrl.start_xr = webxr_helper.start_xr
+                ctrl.stop_xr = webxr_helper.stop_xr
+
+server.start()