An ID is just a number. For example, you could have three materials with the IDs 1, 2, 3.Egert_Kanep wrote: ↑Fri Oct 26, 2018 7:29 am Because I am kind of lost now, with all this ID stuff, does this serve another purpose?
Obviously these cannot be anti-aliased, because this would change the ID completely on the edges (also, the IDs are integers, not floating point numbers).
This is what the material ID AOV is: the raw IDs, not anti-aliased (because that would screw everything up).
But in practice, it is annoying that the masks from this AOV are not anti-aliased. You would e.g. have to render in double resolution and scale everything down after compositing to get a bit of anti-aliasing.
So the idea was to convert the IDs to colors, which can then be anti-aliased, and use tools like Photoshop's magic wand or Blender's difference key node to extract anti-aliased masks from it.