Surface Profile Time Vs. Surface Comparison Time

[[Ty...]]

I have a customer that tends to use the surface profile all around callout on their components. I have been finding that for large parts and millions of points the calculation of the Surface Profile can take hours while the calculation of the Surface Comparison on Actual takes only a few seconds (perhaps a min at most).

From what I understand these two measurements are doing very similar things (measuring the distance at each point from the mesh to the CAD). In fact I have been able to get the same final value for the Surface Profile by just doubling the absolute max or min point on the surface comparison. [The formula for that is 2 * max(abs(max_pt),abs(min_pt))].

Is there a way that the Surface Profile calculation could be sped up or be made to use the faster Surface Comparison algorithm?

[[Ch...]]

Nope, they are not doing the same thing.

As you mentioned in your post a surface comparison computes the distance from actual to nominal (or vice visa depending of the kind of surface profile) in a given alignment.

A surface profile instead computes a optimal alignment first and compute the distance in this optimal alignment afterwards. Of course, the datum system can be used to restrict the alignment.

That means if you are using GD&T Quick Creation three steps can consume the time.

1. Creation of needed help elements (i.e. Patch Compound and Actual surface)
2. Computation of the optimal alignment
3. Distance computation

I would expect that either (1) or (2) is the bottleneck in your case. Maybe it gives some workarounds for your special case but nevertheless this should not take hours. But we will need a deeper look onto a typically project to assist you. Therefore if possible, please provide a typically project via you local GOM contact.