Unity natively imports Cinema 4D files. Unity imports:
Unity does not import Cinema 4D’s Point Level Animations (PLA). Use bone-based animations instead.
Cinema 4D does not export visibility inheritance. Set the Renderer to ‘Default’ or ‘Off’ in Cinema 4D to avoid any difference in the visibility animation between Cinema4D and Unity.
You need to have Cinema 4D installed to import native .c4d files directly into Unity. If you don’t have Cinema 4D installed, use the .FBX format instead. For more information about importing FBX files, see Importing models.
When Unity imports a Cinema 4D file it automatically installs a Cinema 4D plugin and launches Cinema 4D in the background. Unity then communicates with Cinema 4D to convert the .c4d file into a format Unity can read.
The first time you import a .c4d file into Unity, Cinema 4D has to launch in a command line process. This can take a while, but subsequent imports are very quick.
If you are using IK to animate your characters in Cinema 4D, you have to bake the IK before exporting using the Plugins > Mocca > Cappucino menu in Cinema 4D. If you don’t bake your IK prior to importing into Unity, you only get animated locators and no animated bones.
You can speed up file import into Unity by turning off the Embed Textures preference in Cinema 4D before you export. Check the Cinema 4D documentation for instructions.