## Crease Angle

Technical discussions
nickz
Posts: 235
Joined: Fri Jul 26, 2013 3:58 am

### Crease Angle

This is answer to the question in http://www.dynoinsight.com/phpBB3/viewt ... f=2&t=3023, which is off-topic there. It also deserves own thread

It is about the last parameter in IKCMeshTopol.AddSimplex(). It should not be zero. Default should be probably 45. I suggest trying 30 first and playing with this. The objective is to make middle of the surfaces smooth while keeping the edges sharp.

Value of the parameter can vary from place to place. It has effect only for area which includes all immediate neighbour simplexes (star of the simplex)

For non-flat surface two neighbour simplexes joined by an edge always have non-zero angle. The angle is measured between normals (perpendiculars) to the faces. The question KC has to figure out is whether the angle is because of curvature or it is a real edge like edge of a box.

The assumption is that for smooth surfaces the angle should be small. How small is specified by the crease angle parameter. If angle between actual normals is greater than crease angle it is assumed the edge is an actual edge between two smooth pieces of surface