Creo ModelCHECK > teacher > PTC Creo ModelCheck Teacher: Surface Gaps and Overlaps
  
PTC Creo ModelCheck Teacher: Surface Gaps and Overlaps
Surface irregularities are most often found in models that have been imported from other CAD systems.
Why are surface gaps and overlaps dangerous?
If you attempt to make a solid model from a quilt (a bunch of surfaces merged together), the quilt must be watertight (no gaps or overlaps)
If you attempt to create a protrusion with Use Quilt, if the quilt has any gaps in it , Creo Parametric will protrude to infinity through the gaps.
Gaps and overlaps will give you problems in downstream applications such as Pro/MANUFACTURE, Pro/MOLD, and Creo Simulate.
How can surface gaps and overlaps be avoided?
If you find that there are gaps and overlaps in surfaces when they are imported, try re-importing using a different accuracy.
 
* It is recommended that you use CAD/IQ to help analyze surface irregularities that Creo ModelCHECK finds.