Bardia Sadri

I believe this issue was also filed as a bug yesterday. I have a fix for it which should show up in the nightly builds by tomorrow. If you want a workaround, the cause of the crash is the constant zero uv values on your geometry that goes into the polybevel. The bug is in handling degenerate uv maps.

Are you on Windows by any chance? What result do you get when you set “Detriangulate” to “No Polygons”? I can't seem to be able to reproduce this on Mac. There is an outstanding bug with similar circumstances that only surfaces on Windows, but I have only a single example of. The huge overhead of tracking this on Windows (need to have Windows dev setup and compare against another platform side-by-side) under the current development load has kept me from investigating it in absence of more failure cases.

As a side note, normals have nothing to do with Boolean's output. The winding of the polygons determine inside and outside but reversing polygons should only fix problems if you have made a mistake about the semantics of the operation. Most importantly, perturbation of the input should never be required or be a workaround. Please report failures to us through the bug database and preferably lock the inputs to the problematic boolean node in your submitted hip files.

I noticed in fact that Boolean may report non-manifold edges, even when you can't find them in your input geometry, and it's not a mistake. I hadn't considered this before. If you look at the picture here, from the same geometry as above, you can hopefully see that the two highlighted points are both incident to two quads which happen to share yet a third point. Geometrically, this should only happen if the two quads are perfectly coplanar. In practice, however, there's nothing to force a quad to be a planar polygon. A nonplanar quad is in reality the merging of two triangles defined by one of the diagonals of the quad, without specifying which. It is therefore up to the Boolean sop to resolve the ambiguity as a preprocessing step and triangulate all input polygons pretty much the same way the Divide sop would do. In the example in the figure, the diagonal in questions connects the highlighted points and this creates an edge incident to three triangles, namely the one shared by both quads, and the two remaining ones, one from each quad. This would be a non-manifold edge created in preprocessing of the geometry!