Unfolding Orthotrees with Constant Refinement

We show that every orthotree can be unfolded with a 4x4 refinement of the grid faces. This is the first constant refinement unfolding result for orthotrees that are not required to be well-separated.Comment: 42 pages, 39 figures. Preliminary results for orthotrees of degree at most 3 appeared in CCCG 201