add vtkFollower

panel/models/vtk/util.ts

@@ -1,4 +1,5 @@
 import {linspace} from "@bokehjs/core/util/array"
+import {Follower} from "./vtkfollower"
 
 export const ARRAY_TYPES = {
   uint8:   Uint8Array,
@@ -27,6 +28,7 @@ if (vtk) {
   vtkns["CubeSource"] = vtk.Filters.Sources.vtkCubeSource
   vtkns["DataAccessHelper"] = vtk.IO.Core.DataAccessHelper
   vtkns["DataArray"] = vtk.Common.Core.vtkDataArray
+  vtkns["Follower"] = Follower
   vtkns["FullScreenRenderWindow"] = vtk.Rendering.Misc.vtkFullScreenRenderWindow
   vtkns["Glyph3DMapper"] = vtk.Rendering.Core.vtkGlyph3DMapper
   vtkns["HttpSceneLoader"] = vtk.IO.Core.vtkHttpSceneLoader
@@ -80,6 +82,11 @@ if (vtk) {
     vtkns.VolumeMapper.newInstance,
     vtkObjectManager.oneTimeGenericUpdater
   )
+  vtkObjectManager.setTypeMapping(
+    "vtkFollower",
+    Follower.newInstance,
+    vtkObjectManager.genericUpdater
+  )
 }
 
 declare type RGBnode = {

panel/models/vtk/vtkfollower.ts

@@ -0,0 +1,134 @@
+import { vec3, mat4 } from 'gl-matrix'
+
+
+export let Follower: any
+
+const vtk = (window as any).vtk
+
+if(vtk) {
+  const macro = vtk.macro
+  const vtkActor = vtk.Rendering.Core.vtkActor
+
+  function vtkFollower(publicAPI: any, model: any) {
+    console.log("Hello")
+    // Set our className
+    model.classHierarchy.push('vtkFollower')
+
+    // Capture 'parentClass' api for internal use
+    const superClass = { ...publicAPI }
+
+    publicAPI.getMTime = () => {
+      let mt = superClass.getMTime()
+      if (model.camera !== null) {
+        const time = model.camera.getMTime()
+        mt = time > mt ? time : mt
+      }
+
+      return mt;
+    };
+
+    publicAPI.computeMatrix = () => {
+      // check whether or not need to rebuild the matrix
+      if (publicAPI.getMTime() > model.matrixMTime.getMTime()) {
+        mat4.identity(model.matrix)
+        if (model.userMatrix) {
+          mat4.multiply(model.matrix, model.matrix, model.userMatrix)
+        }
+        mat4.translate(model.matrix, model.matrix, model.origin)
+        mat4.translate(model.matrix, model.matrix, model.position)
+        mat4.multiply(model.matrix, model.matrix, model.rotation)
+        mat4.scale(model.matrix, model.matrix, model.scale)
+
+        if (model.camera) {
+          // first compute our target viewUp
+          const vup = vec3.fromValues(model.viewUp[0], model.viewUp[1], model.viewUp[2])
+          if (!model.useViewUp) {
+            const cvup = model.camera.getViewUp()
+            vec3.set(vup, cvup[0], cvup[1], cvup[2])
+          }
+
+          // compute a vpn
+          const vpn = vec3.create();
+          if (model.camera.getParallelProjection()) {
+            const cvpn = model.camera.getViewPlaneNormal()
+            vec3.set(vpn, cvpn[0], cvpn[1], cvpn[2])
+          } else {
+            vec3.set(vpn, model.position[0], model.position[1], model.position[2])
+            const cpos = model.camera.getPosition()
+            const tmpv3 = vec3.fromValues(cpos[0], cpos[1], cpos[2])
+            vec3.subtract(vpn, tmpv3, vpn)
+            vec3.normalize(vpn, vpn)
+          }
+
+          // compute vright
+          const vright = vec3.create();
+          vec3.cross(vright, vup, vpn)
+          vec3.normalize(vright, vright)
+
+          // now recompute the vpn so that it is orthogonal to vup
+          vec3.cross(vpn, vright, vup)
+          vec3.normalize(vpn, vpn)
+
+          model.followerMatrix[0] = vright[0]
+          model.followerMatrix[1] = vright[1]
+          model.followerMatrix[2] = vright[2]
+
+          model.followerMatrix[4] = vup[0]
+          model.followerMatrix[5] = vup[1]
+          model.followerMatrix[6] = vup[2]
+
+          model.followerMatrix[8] = vpn[0]
+          model.followerMatrix[9] = vpn[1]
+          model.followerMatrix[10] = vpn[2]
+
+          mat4.multiply(model.matrix, model.followerMatrix, model.matrix);
+        }
+
+        mat4.translate(model.matrix, model.matrix, [
+          -model.origin[0],
+          -model.origin[1],
+          -model.origin[2],
+        ]);
+        mat4.transpose(model.matrix, model.matrix);
+
+        // check for identity
+        model.isIdentity = false;
+        model.matrixMTime.modified();
+      }
+    }
+  }
+
+  // ----------------------------------------------------------------------------
+  // Object factory
+  // ----------------------------------------------------------------------------
+
+  const DEFAULT_VALUES = {
+    viewUp: [0, 1, 0],
+    useViewUp: false,
+    camera: null,
+  }
+
+  // ----------------------------------------------------------------------------
+
+  Follower = {
+    newInstance: macro.newInstance((publicAPI: any, model: any, initialValues = {}) => {
+      Object.assign(model, DEFAULT_VALUES, initialValues)
+
+      // Inheritance
+      vtkActor.extend(publicAPI, model, initialValues)
+
+      model.followerMatrix = mat4.create()
+      model.camera = vtk.Rendering.Core.vtkCamera.newInstance()
+      mat4.identity(model.followerMatrix)
+
+      // Build VTK API
+      macro.setGet(publicAPI, model, ['useViewUp', 'camera'])
+
+      macro.setGetArray(publicAPI, model, ['viewUp'], 3)
+
+      // Object methods
+      vtkFollower(publicAPI, model);
+    }, 'vtkFollower')
+  }
+
+}

panel/pane/vtk/synchronizable_serializer.py

@@ -239,6 +239,7 @@ def initializeSerializers():
     registerInstanceSerializer('vtkImageSlice', genericProp3DSerializer)
     registerInstanceSerializer('vtkVolume', genericProp3DSerializer)
     registerInstanceSerializer('vtkOpenGLActor', genericActorSerializer)
+    registerInstanceSerializer('vtkFollower', genericActorSerializer)
     registerInstanceSerializer('vtkPVLODActor', genericActorSerializer)
 
 
@@ -575,6 +576,16 @@ def genericActorSerializer(parent, actor, actorId, context, depth):
         'forceOpaque': actor.GetForceOpaque(),
         'forceTranslucent': actor.GetForceTranslucent()
     })
+
+    if actor.IsA('vtkFollower'):
+        camera = actor.GetCamera()
+        cameraId = context.getReferenceId(camera)
+        cameraInstance = serializeInstance(
+            actor, camera, cameraId, context, depth + 1)
+        if cameraInstance:
+            instance['dependencies'].append(cameraInstance)
+            instance['calls'].append(['setCamera', [wrapId(cameraId)]])
+
     return instance
 
 # -----------------------------------------------------------------------------