Blender 3.2+ Boolean modifier buggy transfer of materials

chippwalters · September 14, 2022, 5:37am

Does anyone know about this?

So, every since I started using Blender, I have expected that when I cut into a target object with another object using a boolean modifier, it would not effect the target object material properties. Now, for some reason, the cutout portion of the target object now has all the material properties of the boolean cutter. What is going on?

I know if I explicitly want that behavior, all I need to do is add the proper slot materials to the target object. This gives me the EXACT control I want.

Why has that all changed since Blender 3.2? It worked all the way up to Blender 3.1. Why the huge change and was there any discussion? If there was, I can’t find it. Here’s the issue-- it’s a huge backward step for our workflow. Check out this video to see what I’m talking about.

This has to be a bug, as I can’t find it in any of the release notes anywhere.

HDRdesign-Portugal · December 8, 2022, 2:25pm

Hello Chipp,
I have the same problem with my addon that i made (Plane Cutters Addon).
It is like that the Exact and the Fast solve functions are reversed or something.
My addon does not work anymore due to this change that they have made.
I have noticed this in Blender 3.3.1 LTS. And it starts in version 3.3. The thing is that when you have 2 objects with a material and you make a difference boolean, that your object that has the boolean modifier on it, receives the material of the second object in the cut-out part. And if your second object has no material, the first one gets an empty material slot.
This happens when using the default Exact solver. In version 3.2 this does not happen.
I have noticed it because i used an attribute node in my material and the result is not the same in the 3.3.1 version, compared with the 3.2 version.