ENH: Add CubeMap and SphereMap shader examples.

src/Cxx.md

@@ -842,6 +842,8 @@ This section includes vtkUnstructuredGrid.
 | Example Name | Classes Demonstrated | Description | Image |
 | -------------- | ---------------------- | ------------- | ------- |
 [ColorByNormal](/Cxx/Shaders/ColorByNormal) | vtkOpenGLPolyDataMapper vtkTriangleMeshPointNormals | Modify the shader to color based on model normal.
+[CubeMap](/Cxx/Shaders/CubeMap) | vtkShaderProperty vtkOpenGLPolyDataMapper | Modify the Vertex and Frament shaders to apply a 6-sided cube map.
+[SphereMap](/Cxx/Shaders/SphereMap) | vtkShaderProperty vtkOpenGLPolyDataMapper | Modify the Vertex and Frament shaders to apply a spherical map.
 
 ## Texture Mapping
 

src/Cxx/Shaders/CMakeLists.txt

@@ -20,10 +20,19 @@ endforeach()
 set(KIT Shaders)
 set(NEEDS_ARGS
   ColorByNormal
+  CubeMap
+  SphereMap
 )
 
 set(DATA ${WikiExamples_SOURCE_DIR}/src/Testing/Data)
 add_test(${KIT}-ColorByNormal ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${KIT}CxxTests
   TestColorByNormal ${DATA}/Armadillo.ply)
 
+add_test(${KIT}-CubeMap ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${KIT}CxxTests
+  TestCubeMap ${DATA}/horse.ply ${DATA}/skybox-px.jpg ${DATA}/skybox-nx.jpg ${DATA}/skybox-py.jpg ${DATA}/skybox-ny.jpg ${DATA}/skybox-pz.jpg ${DATA}/skybox-nz.jpg)
+
+add_test(${KIT}-SphereMap ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${KIT}CxxTests
+  TestSphereMap ${DATA}/Bunny.vtp ${DATA}/wintersun.jpg)
+
+
 include(${WikiExamples_SOURCE_DIR}/CMake/ExamplesTesting.cmake)

src/Cxx/Shaders/CubeMap.cxx

+// Inspired by the VTK test Rendering/OpenGL2/Testing/Cxx/TesCubeMap.cxx
+
+#include <vtkSmartPointer.h>
+
+#include <vtkActor.h>
+#include <vtkCamera.h>
+#include <vtkImageFlip.h>
+#include <vtkInteractorStyleTrackballCamera.h>
+#include <vtkJPEGReader.h>
+#include <vtkOpenGLPolyDataMapper.h>
+#include <vtkOpenGLRenderWindow.h>
+#include <vtkPLYReader.h>
+#include <vtkPolyDataNormals.h>
+#include <vtkProperty.h>
+#include <vtkRenderer.h>
+#include <vtkRenderWindow.h>
+#include <vtkRenderWindowInteractor.h>
+#include <vtkShaderProgram.h>
+#include <vtkTexture.h>
+#include <vtkNamedColors.h>
+
+//----------------------------------------------------------------------------
+int main(int argc, char *argv[])
+{
+  if (argc < 8)
+  {
+    std::cout << "Usage: " << argv[0]
+              << " horse.ply skybox-px.jpg skybox-nx.jpg skybox-py.jpg skybox-ny.jpg skybox-pz.jpg skybox-nz.jpg" << std::endl;
+    return EXIT_FAILURE;
+}
+  vtkSmartPointer<vtkNamedColors> colors =
+    vtkSmartPointer<vtkNamedColors>::New();
+  vtkSmartPointer<vtkRenderer> renderer =
+    vtkSmartPointer<vtkRenderer>::New();
+  renderer->SetBackground(colors->GetColor3d("SlateGray").GetData());
+  vtkSmartPointer<vtkRenderWindow> renderWindow =
+    vtkSmartPointer<vtkRenderWindow>::New();
+  renderWindow->SetSize(640,480);
+  renderWindow->AddRenderer(renderer);
+  vtkSmartPointer<vtkRenderWindowInteractor> interactor =
+    vtkSmartPointer<vtkRenderWindowInteractor>::New();
+  interactor->SetRenderWindow(renderWindow);
+  vtkSmartPointer<vtkTexture> texture =
+    vtkSmartPointer<vtkTexture>::New();
+  texture->CubeMapOn();
+
+  vtkSmartPointer<vtkPLYReader> reader =
+    vtkSmartPointer<vtkPLYReader>::New();
+  reader->SetFileName(argv[1]);
+
+  vtkSmartPointer<vtkPolyDataNormals> norms =
+    vtkSmartPointer<vtkPolyDataNormals>::New();
+  norms->SetInputConnection(reader->GetOutputPort());
+
+  for (int i = 0; i < 6; i++)
+  {
+    vtkSmartPointer<vtkJPEGReader> imgReader =
+      vtkSmartPointer<vtkJPEGReader>::New();
+    imgReader->SetFileName( argv[i + 2] );
+
+    vtkSmartPointer<vtkImageFlip> flip =
+      vtkSmartPointer<vtkImageFlip>::New();
+    flip->SetInputConnection(imgReader->GetOutputPort());
+    flip->SetFilteredAxis(1); // flip y axis
+    texture->SetInputConnection(i, flip->GetOutputPort(0));
+  }
+
+  vtkSmartPointer<vtkOpenGLPolyDataMapper> mapper =
+    vtkSmartPointer<vtkOpenGLPolyDataMapper>::New();
+  mapper->SetInputConnection(norms->GetOutputPort());
+
+  vtkSmartPointer<vtkActor> actor =
+    vtkSmartPointer<vtkActor>::New();
+  renderer->AddActor(actor);
+  actor->SetTexture(texture);
+  actor->SetMapper(mapper);
+
+   // Add new code in default VTK vertex shader
+  mapper->AddShaderReplacement(
+    vtkShader::Vertex,
+    "//VTK::PositionVC::Dec", // replace the normal block
+    true, // before the standard replacements
+    "//VTK::PositionVC::Dec\n" // we still want the default
+    "out vec3 TexCoords;\n",
+    false // only do it once
+    );
+  mapper->AddShaderReplacement(
+    vtkShader::Vertex,
+    "//VTK::PositionVC::Impl", // replace the normal block
+    true, // before the standard replacements
+    "//VTK::PositionVC::Impl\n" // we still want the default
+    "vec3 camPos = -MCVCMatrix[3].xyz * mat3(MCVCMatrix);\n"
+    "TexCoords.xyz = reflect(vertexMC.xyz - camPos, normalize(normalMC));\n",
+    false // only do it once
+    );
+
+  // Replace VTK fragment shader
+  mapper->SetFragmentShaderCode(
+    "//VTK::System::Dec\n"  // always start with this line
+    "//VTK::Output::Dec\n"  // always have this line in your FS
+    "in vec3 TexCoords;\n"
+    "uniform samplerCube texture_0;\n"
+    "void main () {\n"
+    "  gl_FragData[0] = texture(texture_0, TexCoords);\n"
+    "}\n"
+    );
+
+  renderer->GetActiveCamera()->SetFocalPoint(0, 0, 0);
+  renderer->GetActiveCamera()->SetPosition(-.4, .2, .15);
+  renderer->GetActiveCamera()->SetViewUp(.3, -.1, .9);
+  renderer->ResetCamera();
+  renderer->GetActiveCamera()->Zoom(1.4);
+  renderWindow->Render();
+
+  vtkSmartPointer<vtkInteractorStyleTrackballCamera> style =
+    vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New();
+  renderWindow->GetInteractor()->SetInteractorStyle(style);
+
+  interactor->Start();
+
+  return EXIT_SUCCESS;
+}

src/Cxx/Shaders/SphereMap.cxx

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+
+  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notice for more information.
+
+=========================================================================*/
+
+#include <vtkSmartPointer.h>
+
+#include <vtkActor.h>
+#include <vtkCamera.h>
+#include <vtkImageData.h>
+#include <vtkInteractorStyleTrackballCamera.h>
+#include <vtkJPEGReader.h>
+#include <vtkOpenGLPolyDataMapper.h>
+#include <vtkOpenGLRenderWindow.h>
+#include <vtkXMLPolyDataReader.h>
+#include <vtkPolyDataNormals.h>
+#include <vtkProperty.h>
+#include <vtkRenderer.h>
+#include <vtkRenderWindow.h>
+#include <vtkRenderWindowInteractor.h>
+#include <vtkShaderProgram.h>
+#include <vtkSkybox.h>
+#include <vtkTexture.h>
+#include <vtkNamedColors.h>
+
+#include <vtkLight.h>
+
+//----------------------------------------------------------------------------
+int main(int argc, char *argv[])
+{
+  vtkSmartPointer<vtkRenderer> renderer =
+    vtkSmartPointer<vtkRenderer>::New();
+  renderer->SetBackground(0.0, 0.0, 0.0);
+  vtkSmartPointer<vtkRenderWindow> renderWindow =
+    vtkSmartPointer<vtkRenderWindow>::New();
+  renderWindow->SetSize(640, 480);
+  renderWindow->AddRenderer(renderer);
+  vtkSmartPointer<vtkRenderWindowInteractor> interactor =
+    vtkSmartPointer<vtkRenderWindowInteractor>::New();
+  interactor->SetRenderWindow(renderWindow);
+
+  vtkSmartPointer<vtkLight> light =
+    vtkSmartPointer<vtkLight>::New();
+  light->SetLightTypeToSceneLight();
+  light->SetPosition(1.0,7.0,1.0);
+  renderer->AddLight(light);
+
+  vtkSmartPointer<vtkXMLPolyDataReader> reader =
+    vtkSmartPointer<vtkXMLPolyDataReader>::New();
+  reader->SetFileName(argv[1]);
+
+  vtkSmartPointer<vtkPolyDataNormals> norms =
+    vtkSmartPointer<vtkPolyDataNormals>::New();
+  norms->SetInputConnection(reader->GetOutputPort());
+
+  vtkSmartPointer<vtkTexture> texture =
+    vtkSmartPointer<vtkTexture>::New();
+  texture->InterpolateOn();
+
+  // mipmapping works on many systems but is not
+  // core 3.2 for cube maps. VTK will silently
+  // ignore it if it is not supported. We commented it
+  // out here to make valid images easier
+  // texture->MipmapOn();
+
+  vtkSmartPointer<vtkJPEGReader> imgReader =
+    vtkSmartPointer<vtkJPEGReader>::New();
+  imgReader->SetFileName(argv[2]);
+  texture->SetInputConnection(imgReader->GetOutputPort());
+
+  vtkSmartPointer<vtkOpenGLPolyDataMapper> mapper =
+    vtkSmartPointer<vtkOpenGLPolyDataMapper>::New();
+  mapper->SetInputConnection(norms->GetOutputPort());
+
+  vtkSmartPointer<vtkActor> actor =
+    vtkSmartPointer<vtkActor>::New();
+  actor->SetPosition(0, 0, 0);
+  actor->SetScale(6.0, 6.0, 6.0);
+  actor->GetProperty()->SetSpecular(0.8);
+  actor->GetProperty()->SetSpecularPower(20);
+  actor->GetProperty()->SetDiffuse(0.1);
+  actor->GetProperty()->SetAmbient(0.1);
+  actor->GetProperty()->SetDiffuseColor(1.0,0.0,0.4);
+  actor->GetProperty()->SetAmbientColor(0.4,0.0,1.0);
+  renderer->AddActor(actor);
+  actor->SetTexture(texture);
+  actor->SetMapper(mapper);
+
+  mapper->AddShaderReplacement(
+    vtkShader::Vertex,
+    "//VTK::PositionVC::Dec", // replace
+    true, // before the standard replacements
+    "//VTK::PositionVC::Dec\n" // we still want the default
+    "out vec3 TexCoords;\n",
+    false // only do it once
+    );
+  mapper->AddShaderReplacement(
+    vtkShader::Vertex,
+    "//VTK::PositionVC::Impl", // replace
+    true, // before the standard replacements
+    "//VTK::PositionVC::Impl\n" // we still want the default
+    "vec3 camPos = -MCVCMatrix[3].xyz * mat3(MCVCMatrix);\n"
+    "TexCoords.xyz = reflect(vertexMC.xyz - camPos, normalize(normalMC));\n",
+    false // only do it once
+    );
+  mapper->AddShaderReplacement(
+    vtkShader::Fragment,
+    "//VTK::Light::Dec", // replace
+    true, // before the standard replacements
+    "//VTK::Light::Dec\n" // we still want the default
+    "in vec3 TexCoords;\n",
+    false // only do it once
+    );
+  mapper->AddShaderReplacement(
+    vtkShader::Fragment,
+    "//VTK::Light::Impl", // replace
+    true, // before the standard replacements
+    "//VTK::Light::Impl\n"
+    "  float phix = length(vec2(TexCoords.x, TexCoords.z));\n"
+    "  vec3 skyColor = texture(actortexture, vec2(0.5*atan(TexCoords.z, TexCoords.x)/3.1415927 + 0.5, atan(TexCoords.y,phix)/3.1415927 + 0.5)).xyz;\n"
+    "  gl_FragData[0] = vec4(ambientColor + diffuse + specular + specularColor*skyColor, opacity);\n"
+    , // we still want the default
+    false // only do it once
+    );
+
+  vtkSmartPointer<vtkSkybox> world =
+    vtkSmartPointer<vtkSkybox>::New();
+  world->SetProjectionToSphere();
+  world->SetTexture(texture);
+  renderer->AddActor(world);
+
+  renderer->GetActiveCamera()->SetPosition(0.0, 0.55, 2.0);
+  renderer->GetActiveCamera()->SetFocalPoint(0.0, 0.55, 0.0);
+  renderer->GetActiveCamera()->SetViewAngle(60.0);
+  renderer->ResetCamera();
+  renderer->GetActiveCamera()->Zoom(1.1);
+  renderer->GetActiveCamera()->Azimuth(0);
+  renderer->GetActiveCamera()->Elevation(5);
+  renderer->ResetCameraClippingRange();
+
+  renderWindow->Render();
+
+  vtkSmartPointer<vtkInteractorStyleTrackballCamera> style =
+    vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New();
+  renderWindow->GetInteractor()->SetInteractorStyle(style);
+
+  interactor->Start();
+
+  return EXIT_SUCCESS;
+}