Add support for temporal mesh in vtkF3DMemoryMesh and scene API

library/private/scene_impl.h

@@ -35,6 +35,7 @@ class scene_impl : public scene
   scene& add(const std::vector<std::filesystem::path>& filePath) override;
   scene& add(const std::vector<std::string>& filePathStrings) override;
   scene& add(const mesh_t& mesh) override;
+  scene& add(const double startTime, const double endTime, MeshCallback&& callback) override;
   scene& clear() override;
   int addLight(const light_state_t& lightState) const override;
   int getLightCount() const override;

library/public/scene.h

@@ -7,6 +7,7 @@
 
 /// @cond
 #include <filesystem>
+#include <functional>
 #include <string>
 #include <vector>
 /// @endcond
@@ -45,6 +46,12 @@ class F3D_EXPORT scene
       : exception(what) {};
   };
 
+  /**
+   * Callback type for animated meshes.
+   * Called with the current time value, should return the mesh for that time.
+   */
+  using MeshCallback = std::function<mesh_t(double time)>;
+
   ///@{
   /**
    * Add and load provided files into the scene
@@ -62,6 +69,11 @@ class F3D_EXPORT scene
    */
   virtual scene& add(const mesh_t& mesh) = 0;
 
+  /**
+   * Add and load provided mesh into the scene
+   */
+  virtual scene& add(const double startTime, const double endTime, MeshCallback&& callback) = 0;
+
   ///@{
   /**
    * Convenience initializer list signature for add method

library/src/scene_impl.cxx

@@ -296,6 +296,35 @@ scene& scene_impl::add(const std::vector<fs::path>& filePaths)
 }
 
 //----------------------------------------------------------------------------
+scene& scene_impl::add(const double startTime, const double endTime, MeshCallback&& callback)
+{
+  if (startTime > endTime)
+  {
+    throw scene::load_failure_exception("startTime must be less than or equal to endTime");
+  }
+
+  vtkNew<vtkF3DMemoryMesh> vtkSource;
+
+  auto wrappedCallback = [cb = std::move(callback)](double time, vtkF3DMemoryMesh* vtkMesh)
+  {
+    mesh_t mesh = cb(time);
+    vtkMesh->SetPoints(mesh.points);
+    vtkMesh->SetNormals(mesh.normals);
+    vtkMesh->SetTCoords(mesh.texture_coordinates);
+    vtkMesh->SetFaces(mesh.face_sides, mesh.face_indices);
+  };
+
+  vtkSource->SetAnimatedMesh(startTime, endTime, std::move(wrappedCallback));
+
+  auto importer = vtkSmartPointer<vtkF3DGenericImporter>::New();
+  importer->SetInternalReader(vtkSource);
+
+  log::debug("Loading animated 3D scene from memory");
+
+  this->Internals->Load({ importer });
+  return *this;
+}
+
 scene& scene_impl::add(const mesh_t& mesh)
 {
   // sanity checks
@@ -306,16 +335,18 @@ scene& scene_impl::add(const mesh_t& mesh)
   }
 
   vtkNew<vtkF3DMemoryMesh> vtkSource;
+  auto importer = vtkSmartPointer<vtkF3DGenericImporter>::New();
+
+  log::debug("Loading 3D scene from memory");
+
   vtkSource->SetPoints(mesh.points);
   vtkSource->SetNormals(mesh.normals);
   vtkSource->SetTCoords(mesh.texture_coordinates);
   vtkSource->SetFaces(mesh.face_sides, mesh.face_indices);
 
-  vtkSmartPointer<vtkF3DGenericImporter> importer = vtkSmartPointer<vtkF3DGenericImporter>::New();
   importer->SetInternalReader(vtkSource);
+  Internals->Load({ importer });
 
-  log::debug("Loading 3D scene from memory");
-  this->Internals->Load({ importer });
   return *this;
 }
 
@@ -327,7 +358,6 @@ scene& scene_impl::clear()
 
   // Clear the window of all actors
   this->Internals->Window.Initialize();
-
   return *this;
 }
 

library/testing/CMakeLists.txt

@@ -10,6 +10,7 @@ list(APPEND libf3dSDKTests_list
      TestSDKInteractorDropFullScene.cxx
      TestSDKInteractorCommand.cxx
      TestSDKSceneFromMemory.cxx
+     TestSDKSceneTemporalFromMemory.cxx
      TestSDKScene.cxx
      TestSDKLog.cxx
      TestSDKMultiColoring.cxx

library/testing/TestSDKSceneTemporalFromMemory.cxx

@@ -0,0 +1,62 @@
+#include "PseudoUnitTest.h"
+
+#include <engine.h>
+#include <image.h>
+#include <log.h>
+#include <scene.h>
+#include <window.h>
+
+#include <cmath>
+#include <sstream>
+#include <string>
+#include <vector>
+
+int TestSDKSceneTemporalFromMemory([[maybe_unused]] int argc, [[maybe_unused]] char* argv[])
+{
+  PseudoUnitTest test;
+
+  f3d::log::setVerboseLevel(f3d::log::VerboseLevel::DEBUG);
+  f3d::engine eng = f3d::engine::create(true);
+  f3d::scene& sce = eng.getScene();
+  f3d::window& win = eng.getWindow().setSize(300, 300);
+
+  // Define mesh data for two frames
+  const std::vector<float> basePoints{ 0.f, 0.f, 0.f, 0.f, 1.f, 0.f, 1.f, 0.f, 0.f, 1.f, 1.f, 0.f };
+  const std::vector<float> translatedPoints{ 0.25f, 0.f, 0.f, 0.25f, 1.f, 0.f, 1.25f, 0.f, 0.f,
+    1.25f, 1.f, 0.f };
+  const std::vector<float> normals{ 0.f, 0.f, -1.f, 0.f, 0.f, -1.f, 0.f, 0.f, -1.f, 0.f, 0.f,
+    -1.f };
+  const std::vector<float> tcoords{ 0.f, 0.f, 0.f, 1.f, 1.f, 0.f, 1.f, 1.f };
+  const std::vector<unsigned int> faceSides{ 3, 3 };
+  const std::vector<unsigned int> faceIndices{ 0, 1, 2, 1, 3, 2 };
+
+  auto meshCallback = [&](double time) -> f3d::mesh_t
+  {
+    if (time < 0.5)
+    {
+      return f3d::mesh_t{ basePoints, normals, tcoords, faceSides, faceIndices };
+    }
+    else
+    {
+      return f3d::mesh_t{ translatedPoints, normals, tcoords, faceSides, faceIndices };
+    }
+  };
+
+  test("add animated mesh with callback", [&]() { sce.add(0.0, 1.0, meshCallback); });
+
+  test("animation time range", [&]() {
+    auto range = sce.animationTimeRange();
+    return std::abs(range.first - 0.0) < 1e-6 && std::abs(range.second - 1.0) < 1e-6;
+  });
+
+  test("quantitative temporal difference", [&]() {
+    sce.loadAnimationTime(0.0);
+    f3d::image frame0 = win.renderToImage();
+    sce.loadAnimationTime(1.0);
+    f3d::image frame1 = win.renderToImage();
+    double error = frame0.compare(frame1);
+    return error > 0.01;
+  });
+
+  return test.result();
+}

vtkext/private/module/vtkF3DMemoryMesh.cxx

@@ -1,14 +1,16 @@
 #include "vtkF3DMemoryMesh.h"
 
-#include "vtkDataArrayRange.h"
+#include "vtkCellArray.h"
 #include "vtkFloatArray.h"
 #include "vtkIdTypeArray.h"
+#include "vtkInformation.h"
 #include "vtkInformationVector.h"
 #include "vtkObjectFactory.h"
 #include "vtkPointData.h"
+#include "vtkPoints.h"
+#include "vtkPolyData.h"
 #include "vtkSMPTools.h"
-
-#include <numeric>
+#include "vtkStreamingDemandDrivenPipeline.h"
 
 vtkStandardNewMacro(vtkF3DMemoryMesh);
 
@@ -51,20 +53,28 @@ void vtkF3DMemoryMesh::SetPoints(const std::vector<float>& positions)
   vtkNew<vtkPoints> points;
   points->SetDataTypeToFloat();
   points->SetData(ConvertToFloatArray<3>(positions));
-
-  this->Mesh->SetPoints(points);
+  this->StaticMesh->SetPoints(points);
+  this->Modified();
 }
 
 //------------------------------------------------------------------------------
 void vtkF3DMemoryMesh::SetNormals(const std::vector<float>& normals)
 {
-  this->Mesh->GetPointData()->SetNormals(ConvertToFloatArray<3>(normals));
+  if (!normals.empty())
+  {
+    this->StaticMesh->GetPointData()->SetNormals(ConvertToFloatArray<3>(normals));
+    this->Modified();
+  }
 }
 
 //------------------------------------------------------------------------------
 void vtkF3DMemoryMesh::SetTCoords(const std::vector<float>& tcoords)
 {
-  this->Mesh->GetPointData()->SetTCoords(ConvertToFloatArray<2>(tcoords));
+  if (!tcoords.empty())
+  {
+    this->StaticMesh->GetPointData()->SetTCoords(ConvertToFloatArray<2>(tcoords));
+    this->Modified();
+  }
 }
 
 //------------------------------------------------------------------------------
@@ -96,17 +106,52 @@ void vtkF3DMemoryMesh::SetFaces(
 
   vtkNew<vtkCellArray> polys;
   polys->SetData(offsets, connectivity);
+  this->StaticMesh->SetPolys(polys);
+  this->Modified();
+}
 
-  this->Mesh->SetPolys(polys);
+//------------------------------------------------------------------------------
+void vtkF3DMemoryMesh::SetAnimatedMesh(double startTime, double endTime, MeshCallback callback)
+{
+  this->AnimatedCallback = std::move(callback);
+  this->TimeRange[0] = startTime;
+  this->TimeRange[1] = endTime;
+  this->IsAnimated = true;
+  this->Modified();
+}
+
+//------------------------------------------------------------------------------
+int vtkF3DMemoryMesh::RequestInformation(vtkInformation* vtkNotUsed(request),
+  vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
+{
+  vtkInformation* outInfo = outputVector->GetInformationObject(0);
+
+  if (this->IsAnimated)
+  {
+    outInfo->Set(vtkStreamingDemandDrivenPipeline::TIME_RANGE(), this->TimeRange, 2);
+  }
+
+  return 1;
 }
 
 //------------------------------------------------------------------------------
 int vtkF3DMemoryMesh::RequestData(vtkInformation* vtkNotUsed(request),
   vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
 {
-  vtkPolyData* output = vtkPolyData::GetData(outputVector->GetInformationObject(0));
+  vtkInformation* outInfo = outputVector->GetInformationObject(0);
+  vtkPolyData* output = vtkPolyData::GetData(outInfo);
+
+  if (this->IsAnimated && this->AnimatedCallback)
+  {
+    double requestedTime = this->TimeRange[0];
+    if (outInfo->Has(vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP()))
+    {
+      requestedTime = outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP());
+    }
+    this->AnimatedCallback(requestedTime, this);
+  }
 
-  output->ShallowCopy(this->Mesh);
+  output->ShallowCopy(this->StaticMesh);
 
   return 1;
 }

vtkext/private/module/vtkF3DMemoryMesh.h

@@ -1,31 +1,38 @@
 /**
  * @class vtkF3DMemoryMesh
- * @brief create vtkPolyData from vectors.
+ * @brief create vtkPolyData from vectors or a callback.
  *
- * Simple source which convert and copy vectors provided by the user
- * to internal structure of vtkPolyData.
- * Does not support point data (normals, tcoords...) nor cell data yet.
+ * Simple source which converts vectors provided by the user
+ * to internal structure of vtkPolyData, or uses a callback  for animated mesh generation.
  */
 #ifndef vtkF3DMemoryMesh_h
 #define vtkF3DMemoryMesh_h
 
 #include "vtkPolyDataAlgorithm.h"
 
+#include <functional>
+
 class vtkF3DMemoryMesh : public vtkPolyDataAlgorithm
 {
 public:
   static vtkF3DMemoryMesh* New();
   vtkTypeMacro(vtkF3DMemoryMesh, vtkPolyDataAlgorithm);
 
   /**
-   * Set contiguous list of positions.
+   * Callback type for animated meshes.
+   * Called with the current time value, should populate the mesh using the Set* methods.
+   */
+  using MeshCallback = std::function<void(double time, vtkF3DMemoryMesh* mesh)>;
+
+  /**
+   * Set contiguous list of positions for a static mesh.
    * Length of the list must be a multiple of 3.
    * The list is copied internally.
    */
   void SetPoints(const std::vector<float>& positions);
 
   /**
-   * Set contiguous list of normals.
+   * Set contiguous list of normals for a static mesh.
    * Length of the list must be a multiple of 3 (or left empty).
    * Must match the number of points specified in SetPoints.
    * The list is copied internally.
@@ -34,7 +41,7 @@ class vtkF3DMemoryMesh : public vtkPolyDataAlgorithm
   void SetNormals(const std::vector<float>& normals);
 
   /**
-   * Set contiguous list of texture coordinates.
+   * Set contiguous list of texture coordinates for a static mesh.
    * Length of the list must be a multiple of 2 (or left empty).
    * Must match the number of points specified in SetPoints.
    * The list is copied internally.
@@ -43,7 +50,7 @@ class vtkF3DMemoryMesh : public vtkPolyDataAlgorithm
   void SetTCoords(const std::vector<float>& tcoords);
 
   /**
-   * Set faces by vertex indices.
+   * Set faces by vertex indices for a static mesh.
    * faceSizes contains the size of each face (3 is triangle, 4 is quad, etc...)
    * cellIndices is a contiguous array of all face indices
    * The length of faceIndices should be the sum of all values in faceSizes
@@ -53,17 +60,30 @@ class vtkF3DMemoryMesh : public vtkPolyDataAlgorithm
   void SetFaces(
     const std::vector<unsigned int>& faceSizes, const std::vector<unsigned int>& faceIndices);
 
+  /**
+   * Set a callback for animated mesh generation.
+   * The callback is invoked at each requested time and should populate the mesh
+   * using SetPoints, SetNormals, SetTCoords, and SetFaces methods.
+   * This switches the mesh to animated mode with the given time range.
+   */
+  void SetAnimatedMesh(double startTime, double endTime, MeshCallback callback);
+
 protected:
   vtkF3DMemoryMesh();
   ~vtkF3DMemoryMesh() override;
 
+  int RequestInformation(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
   int RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
 
 private:
   vtkF3DMemoryMesh(const vtkF3DMemoryMesh&) = delete;
   void operator=(const vtkF3DMemoryMesh&) = delete;
 
-  vtkNew<vtkPolyData> Mesh;
+  vtkNew<vtkPolyData> StaticMesh;
+
+  MeshCallback AnimatedCallback;
+  double TimeRange[2] = { 0.0, 0.0 };
+  bool IsAnimated = false;
 };
 
 #endif