A
TVERTEX class that includes a tolerance value is derived from
VERTEX. The tolerance value represents the maximum distance from the vertex geometry to the ends of all the adjacent edges that are terminated near the vertex. A tolerant vertex is a 0dimensional topological entity that is used to bound an edge or a tedge. The topology of an
ACIS model remains intact.


Two tolerant vertices are coincident if the distance between their points is less than the maximum of their tolerance values. If the tolerance value is less than
SPAresabs, then
SPAresabs is used for coincidence checking.


A tolerant vertex and a vertex are coincident if the distance between their points is less than the maximum of the tolerant vertex tolerance value and
SPAresabs.


The
EDGE class accepts either
VERTEX or
TVERTEX. An edge might be normal in the sense that it has standard
EDGE and
COEDGE entities. However, an
EDGE might be required to accept one or more
TVERTEX entities instead of normal
VERTEX entities to create a valid topology.


When solving for a tolerant vertex position, a smart estimate of a solution position is used when curve/surface and curve/curve intersections fail to determine the vertex location.
