Overview of the Patching Method

The method used to patch a design will vary according to design shape and user experience. The general method is to construct plines delineating zones on the surface which have "similar" shape, such as inflection points, areas of similar curvature, These plines, together with FOB, FOS, knuckle lines, will be used to define the patch boundaries. The patches will be generated on this mesh of boundary curves.

Patches need to have common boundaries and end points to enable continuity to be applied between neighboring patches. In previous versions of Lines, patch corners and edges could be up to 0.1mm apart. This caused problems later when the patches were stitched together in Surface, so now patch corners and edges are pulled together (Boundary Continuity) if they are within the patch tolerance (the tolerance can be changed from the User Parameters dialog).

Therefore, to maintain continuity across patches, the same boundary curves and corners must be used between adjacent patches.