This interface allows to specify a set of shader replacement strings (and NOT the full shader code) which are a low level mechanism in how VTK manages the shader construction depending on the data type and involved mappers. The related properties editor frame help of ParaView shows a short documentation about what is expected. Basically it’s a JSON list that describes, for each replacement: the type of shader, the shader string to search, the replacement string. Clearly, it is a very advanced feature as you must know/guess the shader code.
Hope this helps.
