I once saw a tutorial about how to fade a model in C4D that is made by multiple objects. Let's say a car , where you would have seperate objects for the wheels, doors, windows, etc.
The tutorial outlined the problem, that when you decrease the transparency of each material, you would start to see through the parts and see what's behind the objects in the front. If you would see the car from the side, you would start to see the doors in the back.
After that, the tutorial showed an approach of how to fade the model in a clean way. The result could be compared by reducing the oppacity on a rendered image.
I went through all my bookmarks, but I can't find this tutorial anymore. After searching the web for the last hours, I also gave up on google.
If anyone knows which tutorial I'm talking about, please post a link here. This drives me nuts that I can't find it any more.