docs(blogs): add sample code we use to showcase blogs

examples/blogs/vtk-9.4/pipeline.py

@@ -0,0 +1,133 @@
+import vtk
+
+from trame.app import get_server
+from trame.ui.vuetify3 import VAppLayout
+from trame.widgets import vtk as vtk_widgets, vuetify3 as v3
+from trame.decorators import TrameApp, change
+
+
+def setup_vtk():
+    renderer = vtk.vtkRenderer()
+    render_window = vtk.vtkRenderWindow()
+    render_window.AddRenderer(renderer)
+    render_window.off_screen_rendering = True
+
+    render_window_interactor = vtk.vtkRenderWindowInteractor()
+    render_window_interactor.SetRenderWindow(render_window)
+    render_window_interactor.GetInteractorStyle().SetCurrentStyleToTrackballCamera()
+
+    # Pipeline
+    sphere_source = vtk.vtkSphereSource(
+        theta_resolution=16,
+        phi_resolution=16,
+    )
+
+    cone_source = vtk.vtkConeSource(
+        radius=0.1,
+        height=0.2,
+        resolution=30,
+    )
+
+    normals = vtk.vtkPolyDataNormals()
+    normals.compute_cell_normals = 1
+    normals.SetInputConnection(sphere_source.GetOutputPort())
+
+    cell_centers = vtk.vtkCellCenters()
+    cell_centers.SetInputConnection(normals.GetOutputPort())
+
+    glyph_mapper = vtk.vtkGlyph3DMapper()
+    glyph_mapper.SetInputConnection(0, cell_centers.GetOutputPort())
+    glyph_mapper.SetInputConnection(1, cone_source.GetOutputPort())
+    glyph_mapper.orient = True
+    glyph_mapper.orientation_array = "Normals"
+
+    # Rendering
+    actor = vtk.vtkActor()
+    actor.SetMapper(glyph_mapper)
+    renderer.AddActor(actor)
+    renderer.ResetCamera()
+    render_window.Render()
+
+    return render_window, sphere_source, cone_source
+
+
+@TrameApp()
+class Viewer:
+    def __init__(self, server=None):
+        self.rw, self.sphere, self.cone = setup_vtk()
+        self.server = get_server(server)
+        self._build_ui()
+
+    @property
+    def ctrl(self):
+        return self.server.controller
+
+    @change("cone_resolution", "cone_height", "cone_radius")
+    def update_cone(self, cone_resolution, cone_height, cone_radius, **_):
+        self.cone.resolution = cone_resolution
+        self.cone.height = cone_height
+        self.cone.radius = cone_radius
+        self.ctrl.view_update()
+
+    @change("sphere_resolution")
+    def update_sphere(self, sphere_resolution, **_):
+        self.sphere.theta_resolution = sphere_resolution
+        self.sphere.phi_resolution = sphere_resolution
+        self.ctrl.view_update()
+
+    def _build_ui(self):
+        with VAppLayout(self.server, fill_height=True) as self.ui:
+            with v3.VCard(
+                style="position: absolute; top: 1rem; left: 1rem; z-index: 1; width: 20%;"
+            ):
+                v3.VCardTitle("Cone")
+                v3.VDivider()
+                with v3.VCardText():
+                    v3.VLabel("Resolution: {{ cone_resolution }}")
+                    v3.VSlider(
+                        v_model=("cone_resolution", 30),
+                        min=3,
+                        step=1,
+                        max=24,
+                        hide_details=True,
+                    )
+                    v3.VLabel("Height: {{ cone_height }}")
+                    v3.VSlider(
+                        v_model=("cone_height", 0.2),
+                        min=0.01,
+                        step=0.01,
+                        max=0.5,
+                        hide_details=True,
+                    )
+                    v3.VLabel("Radius: {{ cone_radius }}")
+                    v3.VSlider(
+                        v_model=("cone_radius", 0.1),
+                        min=0.01,
+                        step=0.01,
+                        max=0.2,
+                        hide_details=True,
+                    )
+                v3.VCardTitle("Sphere")
+                v3.VDivider()
+                with v3.VCardText():
+                    v3.VLabel("Resolution: {{ sphere_resolution }}")
+                    v3.VSlider(
+                        v_model=("sphere_resolution", 16),
+                        min=8,
+                        step=1,
+                        max=32,
+                        hide_details=True,
+                    )
+
+            with vtk_widgets.VtkRemoteView(self.rw, interactive_ratio=1) as view:
+                self.ctrl.view_update = view.update
+                self.ctrl.view_reset_camera = view.reset_camera
+
+
+def main():
+    app = Viewer()
+    app.server.start()
+
+
+if __name__ == "__main__":
+    main()