vtkImageActor does not update mapper before vtkImageActor::HasTranslucentPolygonalGeometry()
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
Problem is that when vtkImageSlice::RenderOpaqueGeometry() is called the first time, the mapper has never been updated, the image data has no scalars array, and vtkImageSlice::Render() is called within vtkImageSlice::RenderOpaqueGeometry(). It updates the mapper, so next time RenderTranslucentPolygonalGeometry() is called, Render() is called a second time (because this time I have a scalars array).