Stereo problem with GPU Volume Mappers

I want to use stereo anaglyph with vtkOpenGLGPUVolumeRayCastMapper or vtkGPUVolumeRayCastMapper but stereo doesn’t work with GPU mappers.
Stereo works perfectly fine with vtkFixedPointVolumeRayCastMapper.

Attached screenshot shows left skull rendering with vtkOpenGLGPUVolumeRayCastMapper and right with vtkFixedPointVolumeRayCastMapper. If you use red and blue anaglyph glasses, you will clearly see the difference. There is no depth in the left skull which is rendered by GPU mapper, but depth is clearly seen in the right skull rendered by CPU mapper.

Any solution to this issue?

Thanks.