I am trying to create a "stamp" in Blender from overlapping objects, but boolean Modifier doesn't work properly if some faces have the same z value. I have tried different sequences of using boolean and join.
I would like to have an easy way to set the depth of the stap to a specific height for easy handling.
I think the best solution would be to create one face from the outline of the top down projection and extending it in the z-axis, so the boolean modifier works correctly without coplanar faces, but I don't know how to do that.
I would also appreciate other possible solutions to this problem. I know my issue is having coplanar faces, but how do I clean them up in my case? Thanks in advance.