After I have updated a SketchUp model, how to import my scene again in LumenRT by finding the previously set items?
The correct workflow is:
1. Export your model from SketchUp to LumenRT
2. Create all your wonderful nature around it and even change material on the model
3. Re-export from SketchUp and all your changes in the LumenRT scene model are preserved including any new materials you added to the model inside LumenRT.
You can re-export as many times as you like. Remember, LumenRT needs the same SketchUp file name. If you have renamed the SketchUp file, LumenRT will consider it's a new scene
See video below