I've been looking at a way to print mini-Bonsai trees for aquarium aquascaping purposes. My plan was to print a 3D structure, and then glue moss onto it, so that once grown, it would look like a tree.
My first attempt was a solid shape. And that looked OK, but then I realized I could create a Voronoi tiling that would give it a cholla-like effect but shaped like a bonsai tree. That would also allow fish and the greens to live in the tree. I'll update once the moss has had a chance to grow.
The original design is in OpenScad, but soon after I pulled it into meshmixer and was able to generate the skeletal tiling by reducing the mesh and then taking the dual.
For some bizarre reason I didn't have problems with overhangs here. Using 0.4mm seems to increase overhang possibility.