Optimize CAD
Fix gaps between stitched edges and vertices to make the actual geometry of the surfaces consistent with the model topology.
 Navigate to the Geometry ribbon.
 While in idle mode, select surfaces.
 Rightclick and select .

In the dialog, enter a geometric tolerance value.
If a gap is found to be bigger than the specified tolerance, then the surface and edge geometries will be morphed parametrically and in 3D, if necessary, to make the gap smaller than the tolerance. In addition, nonessential degenerate edges are removed.
 Click OK.
The original geometric entity IDs are also preserved. The same functionality is used for the Optimize for CAD option in the Geometry Export Options dialog.
Example: CAD Optimization
This example demonstrates the difference in results when using the Optimize CAD tool
to update geometry that has previously been repaired with topologybased geometry
cleanup operations, for example, toggle/equivalence/replace edges and replace
points.The geometry below was repaired using only topologybased geometry cleanup
operations. After the geometry was meshed, you can see that some of the elements
have become distorted. After untoggling the edges, there is still a large gap in the
geometry.
The geometry below was repaired using topologybased geometry cleanup operations and
then updated with the Optimize CAD tool. After the geometry was meshed, you can see
that there are no distorted elements. After untoggling the edges, there is not a gap
in the geometry.