# Tricky Surface Challenge

ChrisWard2k2

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posts: 2

Registered: 2011-11-22

Message 1 of 5

Tricky Surface Challenge
22-10-2002 07:29 . am | View his/her posts only
Attached file (v6.51) has a wireframe that requires surfacing. Faces must be accurate, smooth and curvature continuous. Anyone able to achieve this?
Chris Ward

Vance

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posts: 0

Registered: 2002-8-28

Message 2 of 5

22-10-2002 03:28 . pm | View his/her posts only
Do you really mean that the surfaces must be curvature continuous? It is impossible to interpolate a set of non-curvature continuous curves with a curvature continuous surface. And since the wireframe is a bunch of lines and arcs, the underlying curves are not curvature continuous.

In fact, since the arcs around the bottom profile are not tangent with the straight lines, it is impossible to even create tangent continuous surfaces with the given input.

Let me know if that is the geometry that you really need to interpolate, and I can take a whack at it.

ChrisWard2k2

Newbie

posts: 2

Registered: 2011-11-22

Message 3 of 5

24-10-2002 06:07 . am | View his/her posts only
Hi SurfaceDude, yep, this is the geometry required. This data is a test put to one of our Turkish Dealers by a potential customer; I suspect it is a "gauntlet" from another CAD supplier. I agree that some change to the wireframe geom has to be accepted to produce smooth surfaces. The arcs around the bottom profile are not tangent at their radius of 25. However, I have tried reducing them to R20, making them tangent with the lines, but this has not really helped in terms of the way the overall surface shape is affected. The orange curves are original geom but these I think could be replaced by curves of essentially the same shape and position but curvature improved. What do you think?

Vance

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posts: 0

Registered: 2002-8-28

Message 4 of 5

28-10-2002 09:40 . am | View his/her posts only
Here is an attempt with the arcs around the bottom changed to R20. You can probably take the approach here and come up with better surfaces if you make the input curves be curvature continuous. This solution is a bit of work, but it does a pretty good job.

ChrisWard2k2

Newbie

posts: 2

Registered: 2011-11-22

Message 5 of 5

28-11-2002 08:41 . am | View his/her posts only
The file you defined was forwarded-on to Turkey. Unfortunately it had been saved in v7 so they couldn't access it at the time but they can now! This solution gives a very pleasing result, looks like we have passed the test. Thanks for your help SurfaceDude