Aura Material Converter
Extract the “AuraMaterialConverter” archive to “../MAXON/Cinema 4D R[version_number]/plugins”.
Press the “Go!”-button to convert all Arnold Materials in the project to Cinema 4D standard materials and replace them on the on the corresponding objects.
Tick the checkbox, if you want to delete your old Arnold materials.
Attention: Use a duplicate of your C4D-file for conversion. Do not save your file after running the converter the original file or you may your material data.