Does Paraview support custom shaders?

[mwestphal (Mathieu Westphal (Kitware))]

You can write your own and store them using this interface.

Some examples here:

Is there any documents or examples for Custom shader / Shader Replacement?

I am trying to shading a point cloud in point gaussian representation. But I cannot figure out how to get vertex normal or how to get camera position through shader replacement/ custom shader. Could someone give me some hints? Thanks!