multi-component, parallel volume rendering using vtk

Hi All,

I am trying to do a parallel multi component volume rendering using vtk in python. To do this I developed a custom, parallel aware reader using vtkpythonalgorithmbase. Currently, my approach to achieve this is as follows:

step 1: create volume rendering on each rank with same viewpoint and other settings.
step 2: Then the final image is obtained from compositing images from each rank using compositergbapass and vtkimagerendermanager.

This method works well for volume rendering with single component. However, I am facing some issues with compositing when using multiple components. Where, one component decides the opacity and other decides color.

I have tried both independent components on and off. I have also tried using vtkfixedpointvolumeraycastmapper and gpuraycastmapper. Using any of the above combinations, the rendering hangs.

I attached my script below. Any help would be appreciated.

Hari. (8.1 KB)