VTK: Rendering/VolumeOpenGL2 -> Volume Relation

| VTK 9.3.1

### VolumeOpenGL2 → Volume Relation

File in Rendering/VolumeOpenGL2 | Includes file in Rendering/Volume
--- | ---
vtkMultiBlockUnstructuredGridVolumeMapper.h | vtkUnstructuredGridVolumeMapper.h
vtkMultiBlockVolumeMapper.h | vtkVolumeMapper.h
vtkOpenGLGPUVolumeRayCastMapper.h | vtkGPUVolumeRayCastMapper.h
vtkOpenGLProjectedTetrahedraMapper.h | vtkProjectedTetrahedraMapper.h
vtkOpenGLRayCastImageDisplayHelper.h | vtkRayCastImageDisplayHelper.h
vtkOpenGLVolumeOpacityTable.h | vtkVolumeMapper.h
vtkSmartVolumeMapper.h | vtkVolumeMapper.h
vtkVolumeShaderComposer.h | vtkVolumeMapper.h