Is there a way to create a 3d shape by using intersecting planes? The image shows 6 planes that define an enclosed cuboid. I tried joining the planes, then using the knife tool with self-intersection, but the result did not generate vertices where three planes intersect. I know I could do it in steps by first joining the 4 vertical planes and using the knife tool, then join that to the horizontal planes and repeating, but that becomes tedious for more complex shapes.
This was done in 2.79, but I'm open to suggestions for 3.0 as well.