1 Reply Latest reply on Jul 13, 2007 1:21 PM by Ricky Jordan

    Curves ntangents to surfaces

    Andrew Nelson

      I have a Geomagic surfaced model that has some overlappingsurfaces.  I have deleted those surface and now need to createcurves/splines that are tangent to other other bounding surfaces,so as to maintain continuity.  How do I create those tangentcurves?

      Please refer to attached file as example.  The surfaces inthis file were created in Alias, and exported as IGS.


        • Curves ntangents to surfaces
          Ricky Jordan

          I've worked with some reverse engineering surface data recently. It can definitely be a different animal as compared to surface created using normal methods. One thing you have to keep in mind is that the curvature between surfaces created by the reverse engineering software are quite often not perfectly continuous. A Deviation Analysis of existing edges on your import will show that. The reason I mention this is that it can have an effect on area you are patching. If you have nice clean edges to patch it makes the job pretty easy. The edges on your example are pretty clean.

          For the example you sent, I would start with the Boundary surface tool (see image) on patches with open sides. You can put some 3D sketch splines in if you want more control (my example didn't). It can be a little flaky sometimes, but you can add tangent or equal curvature relations to a surface face (select spline, surface and edge of surface where spline is attached - see image copied from the help).

          The Boundary Surface I created still had a view variances in the angles between surfaces when a Deviation Analysis was applied, but I think it is due to the U-V direction of the existing edges of the surfaces.

          If you have a completely closed patch, I would start with the surface fill tool. It can be used on open boundaries too, but you'll need to create a sketch to form the edge of your patch.

          I'm not a surfacing guru by any means but this has worked for me many times. I hope this helps.

          Best Regards,