Three questions on CPU load

Unity Engine
1
  1. If a mesh is in a layer not rendered by any camera, does it drain CPU power?
  2. What if a mesh is completely obscured by another object?
  3. And what if it’s only partly obscured? Let’s say, a person standing behind a tree and only the arms are visible?
2

  1. if that object has scripts that are executing, or a rigidbody, etc., then it still uses CPU. For rendering purposes, a non-rendered object is extremely cheap. It’s not exactly “free”, as some code has to check whether it’s layer matches the camera, but compared to the cost of actual rendering, the cost can be assumed to be zero.

  2. Currently Unity does not do occlusion culling or occluder fusion out of the box. So an object that is completely behind some other object is still rendered. However, you can implement some occlusion scheme manually; for a simple example see Nature Demo, where the water is turned off when it is behind the hill.

  3. Does not require answer already (see point 2) :slight_smile:

3

Thank you for your thorough and speedy reply.