Method UpdateOpacityTransferFunction

Rendering/VolumeOpenGL2/vtkVolumeInputHelper.cxx:99–144

}

int vtkVolumeInputHelper::UpdateOpacityTransferFunction(
  vtkRenderer* ren, vtkVolume* vol, unsigned int component, int blendMode, float samplingDist)
{
  vtkVolumeProperty* volumeProperty = vol->GetProperty();

  // Use the first LUT when using dependent components
  unsigned int lookupTableIndex = volumeProperty->GetIndependentComponents() ? component : 0;
  vtkPiecewiseFunction* scalarOpacity = volumeProperty->GetScalarOpacity(lookupTableIndex);

  auto volumeTex = this->Texture.GetPointer();
  double componentRange[2];
  if (scalarOpacity->GetSize() < 1 ||
    this->ScalarOpacityRangeType == vtkGPUVolumeRayCastMapper::SCALAR)
  {
    for (int i = 0; i < 2; ++i)
    {
      componentRange[i] = volumeTex->ScalarRange[component][i];
    }
  }
  else
  {
    scalarOpacity->GetRange(componentRange);
  }

  if (scalarOpacity->GetSize() < 1)
  {
    scalarOpacity->AddPoint(componentRange[0], 0.0);
    scalarOpacity->AddPoint(componentRange[1], 0.5);
  }

  int filterVal = volumeProperty->GetInterpolationType() == VTK_LINEAR_INTERPOLATION
    ? vtkTextureObject::Linear
    : vtkTextureObject::Nearest;

  this->OpacityTables->GetTable(lookupTableIndex)
    ->Update(scalarOpacity, componentRange, blendMode, samplingDist,
      volumeProperty->GetScalarOpacityUnitDistance(component),
#ifndef GL_ES_VERSION_3_0
      filterVal,
#else
      vtkTextureObject::Nearest,
#endif
      vtkOpenGLRenderWindow::SafeDownCast(ren->GetRenderWindow()));

  return 0;
}

int vtkVolumeInputHelper::UpdateColorTransferFunction(
  vtkRenderer* ren, vtkVolume* vol, unsigned int component)