Maya Scene Converter
Work in progress
https://github.com/mhdmhd/MayaSceneCo...
Maya Scene Converter is a python-based Qt tool for converting scenes from a render engine to another in Maya, it is not a perfect conversion and it depends on rules files and how good they are but gives you a great head start.
Features
Creates rules to convert from a source render engine to a target render engine
Easy UI to create, save and load the rules
Supports all shading related nodes: Materials,Textures,Utilities and Lights
Converts all the scene or selected objects
Scans the scene for any node or only what belongs to the source engine
Some ready examples of rules files (not very precise but very functional)
Prints info about all conversions
Tested with Windows only but could work on other operating systems
Tested with Maya 2018+ but could work on previous versions