UNFOLD3D Generation 6 User Manual

UNFOLD3D Generation 6 User Manual: "3.1 - Modeling Rules
Unfold3D requires the input mesh to respect a certain number of modeling rules. These rules are generally respected as rules of general modeling hygiene, but they become compulsory to apply Unfold3D's mathematical algorithms:

Rule 1: no edge with 3+ neighboring polygons (see figure). All edges must belong to at most two polygons.

Rule 2: no butterfly point (see figure). A vertice cannot have more than two border edges (ie: edges with only one neighboring polygon) connected to it.

Rule 3: the imported file must comply with OBJ standards, and not use the the ' relative vertex numbering ' mode.

Note that these rules do not limit the possibilities of modeling:
Unfold3D has no problem dealing with holes in the mesh;
the modeling rules are written for triangles, but Unfold3D is perfectly fit to deal with quads or n-gons - Unfold3D will triangulate the mesh anyway, and try to avoid as much as possible the forbidden cases.

Note that non-convex n-gons may cause problems though:"