I'm sort of new to blender. I'm having problems with overlapping meshes. when I render, the strange blackish effect is observed. Specifically, I'm trying to model a 6-point star ("star of david"). e.g., see: https://en.wikipedia.org/wiki/File:Star_of_David.svg
I start with a non filled triangle, duplicate it and scaling it down in edit-mode, and then creating 3 quad faces. I duplicate in object mode, rotate 180deg around the z axis, and do a bool union. However, in the resulting object, the vertices don't land on the intersection of the triangle edges, so I can't delete the overlapping regions.
How can this be done? Thanks.