Convexity | Value | Example |
|---|
| convex | PK_EDGE_convexity_convex_c |  |
| concave | PK_EDGE_convexity_concave_c |  |
| variable
the convexity varies along the edge | PK_EDGE_convexity_variable_c |  |
| smooth flat
parallel surface normals, both faces have zero face curvature | PK_EDGE_convexity_smooth_flat_c |  |
| smooth convex
edge convexity is smooth, both faces have positive curvature (or one has zero, one has positive) | PK_EDGE_convexity_smooth_cvx_c |  |
| smooth concave
edge convexity is smooth, both faces have negative curvature (or one has zero, one has negative) | PK_EDGE_convexity_smooth_ccv_c |  |
| smooth inflection
edge convexity is smooth, faces have opposite curvature | PK_EDGE_convexity_smooth_inf_c |  |
| smooth variable edge convexity is smooth, some parts are smooth convex, some parts are smooth concave | PK_EDGE_convexity_smooth_var_c |  |
| knife convex
surface normals are anti-parallel and the sum of the curvatures is non-negative | PK_EDGE_convexity_knife_cvx_c |  |
| knife concave
surface normals are anti-parallel and the sum of the curvatures is non-positive | PK_EDGE_convexity_knife_ccv_c |  |
