KOMPAS-3D v23

Surface self–intersection as a mathematical object is not an error as such. In the meantime, self–intersection of a face of a part is a modelling error, because it is not possible to manufacture such a part.

For example, you cannot assign Thicken, since the result will inherently represent a faulty solid. However, you can thicken a segment of a surface without intersections if you separate this segment from the rest of the surface using truncation.

Another example: extrusion up to surface It is impossible if the section of the element is projected onto a surface in the area where it intersects itself. If the section is projected to a segment of a surface without self–intersections, then extrusion is possible.

In most cases, the surfaces are created to be used as faces of solids, that’s why the Surface by point grid command and some other commands include checking for self–intersection. If checking is enabled, it is performed after the surface is created: if a self-intersection is present, the surface is marked with the error mark in the Design tree. It may be necessary to correct this error depending on which part of the surface you are intending to use.