An asset can look correct in its source application and still fail after import into Cinema 4D. Treat material translation as a translation problem between tools, with shader mapping and channel packing checked on both sides.
For Cinema 4D, check color space, channel packing, texture resolution, and shader assumptions as one system. A material translation pass should set a measurable budget and explain any visible compromise.
Compare base color, roughness, metalness, normal orientation, opacity, and emissive output under equivalent lighting. Apply this material translation guidance to the actual Cinema 4D delivery path.