If you haven’t jumped on any of the many great third party renderers that are available for Cinema 4D either due to price or need, not to worry. Cinema 4D has a fairly capable and really easy to use physical render. The renderer also includes an option for global illumination.
a comprehensive look at Global Illumination in Cinema 4D
Even though it is really simple to use, there are still some things that should be considered. This is especially important when working with creating a rendering of an interior, no matter what kind of rendering engine you are using. Any type of rendering really comes down to managing the lighting, shadows and the scene itself.
Here, Samuel Winter (also known as Digital Meat) offers a comprehensive look at using C4D’s Physical Renderer along with GI, for rendering interiors. This includes some global illumination methods and tips, and a look at reducing the light and shadow artifacts for some nice clean renders. If you understand what is going on when you do a physical render, you can best manage render times and render quality to get the results that you are looking for.