How to prepare the geometry to avoid light leaking? Chap. 2


I just posted another question regarding how the geometry should be prepared to avoid light leaking. This is a different case. Please see the images attached with an example.

I come across this situation all the time when I’m modeling a complex object. Let’s say that I want the whole object of the attached pictures to be a single mesh (blue + red). In the process of modeling, I separate both as different meshes to avoid extra geometry.

My question is:

  • A.- Should I close the gap between the meshes on each part so each part is a solid object? This means that when I connect both parts to get a single mesh there will be a pverlapping geometry.
  • B.- Can I leave each part of the geometry open and connect them as a single mesh? This means that the edge of both parts will be overlapping but the geometry is a bit different, as one part may have more points than the other, or in a different position.

Again, I want to learn how to prevent light leaking on my meshes (I know that UVs have to be mapped properly, I took that for granted).