9 Replies Latest reply on Aug 12, 2010 4:12 AM by 1-SOSNOE

    Re-positioning UV-curves



      So I´m using the surface wizard, guided creation and I extract BSplines from the surface. I can choose to re-position certain UV-curves but not the externals ones. Why? My point is that in previous steps I took my time to cut out the unwanted areas (picture 1), yet when in the surface wizard I get an area that´s bigger again than my desired surface (picture 2).


      Or did have I misinterpreted those steps? Didn´t I need to cut out so closely and exactly with the pencil-tool, selecting individual triangels? Would it have been sufficient to go roughly around the edges?


      And when I´m finished, I get a surface like in picture 3. I can not draw on that surface and I don´t know how to cut out the unwanted areas . What do?


      I hope I could explain my thoughts. If You didn´t understand I can try to upload more screenshots.

        • Re: Re-positioning UV-curves

          Hi Goekhan,


          The sub-mesh that you prepared by painting out unwanted areas - the portions that you painted out are not taken into account when the Bspline surface is calculated and extracted, but like all the other surface extraction types, the surface is extended to it's natural boundaries (bspline patches are always square by nature) so that you can trim it against other surfaces in your model and make solid.


          Perhaps you can post an example file of what you are trying to achieve in the end.





            • Re: Re-positioning UV-curves
              Anna Wood

              Looks like he is working with a scan of the backside of a violin.  Doing a bit of reverse engineering.....

              • Re: Re-positioning UV-curves

                Hello Mark,


                I think I understand that the BSplines can only form an rectangle, but still the rectangle area is considerably bigger than my cut out area.

                My goal is a surface like the one I cut out, picture 1.

                Picture 2 shows the UV-curves (20 each side). As You can see there is a red rectangle. Now wouldn´t the area of the red rectangle be enough? Why are there up to 3 Bspline curves that are out of my object? Isn´t this wasting? Of course I can pull the lines closer in like in picture 3, for analysis reasons.

                It just kind of bothers me, that when I finish that last step I get picure 4. Now I can barely see the object I want to achieve.


                I guess the next step is to make some 3D-sketches (Bsplines) and cut out again.

                  • Re: Re-positioning UV-curves
                    Robert Stupplebeen

                    I think you may be going down an unnecessarily difficult route.  To create that geometry I believe that a boundary surface would create accurate geometry for your purposes.  It may be worth creating the geometry in quarters and then mirror to get the other half.  I hope this helps.


                    Rob Stupplebeen

                    • Re: Re-positioning UV-curves
                      Kevin De Smet

                      I can only think of, that a patch just like a spline curve, can be a little unpredictable/undesirable near its endpoints.

                      • Re: Re-positioning UV-curves

                        Hello Goekhan,


                        You can use the rectangular patch created by the ScanTo3D extracted surface, you'll just have to trim it back to the profile of the violin back outline. You can use the S23D Curve wizard to derive this boundary curve if you like or trace a 2D or 3D curve directly on the mesh. Then use this sketch curve to trim away the excess part of the rectangular patch. If you find that the edge is "wavy" to an undesirable degree, then you have to reuse the  extracted 3D sketch curves along with the boundary curve of the profile can build a boundary surface with two directions (direction 1 curves = the 3D sketch curves extracted) and (direction 2 curves = the segments of the boundary sketch curve) you can then "cap" the front and back ends with a fill surface.


                        What ever results, remember that you can go back into (Edit) the 3D sketch curves which were created by the ScanTo3D extracted fitted bspline surface, and cleanup, smooth out and simplify these curves (using display curvature) to get a better result and remove and irregularities incurred from the scanned data.