5 Replies Latest reply on Jul 8, 2014 9:18 PM by Andre Cardadeiro

    Gaps between adjacent surfaces normal?

    Andre Cardadeiro

      I have my Document Properties->ImageQuality-> Shaded and Draft options to the highest setting, reducing tessellation.  But, when modeling two complex surfaces next to each other (using one edge of the first surface as one of the boudaries for the second surface), and I zoom in real well, I'll notice the shaded surface doesn't line up with that surface's edge.  Is there a graphic limitation in Solidworks to visually produce tight surface "fills" right up to the surface edge? 

       

      Obviously, if I dial back the Shaded resolution, it gets much worse.  I have fairly high end graphics and computer hardware.  (SW 2013 SP5)

       

      What I notice is that Knit Surface will then display that a Gap is found between these two surfaces, and I can see it as well, but only when zoomed in quite a bit.  Why would Solidworks allow a gap between two surfaces who supposedly share one side?  Is this also a limitation of SW, requiring the use of Knit Surfaces often to create water-tight surfaces?

       

      Or, are there additional settings I can adjust?

        • Re: Gaps between adjacent surfaces normal?
          Jerry Steiger

          Andre,

           

          It may be due to the way you built your surfaces. Did you build the common edge off of the same sketch, or did you use a sketch to make the first edge and then use the first edge to define the second surface? Whichever method you used, try doing the other and see if it helps.

           

          How are you making the surfaces? Loft, Boundary, Fill, Sweep, other?

           

          Jerry S.

            • Re: Gaps between adjacent surfaces normal?
              Andre Cardadeiro

              SW_SurfaceGaps.jpg

              Above pic:  I am selecting the edge of the other surface for Direction 2, and you can see that it leaves some gaps between both surfaces.

               

              I am projecting two spline sketches from a top plane and a right plane, ending up wtih a curve.  From the projected curve, I create a four sided boundary surface filling the top plane, and then another four sided boundary surface filling the right plane, using the projected curve as the shared edge.  Fairly standard stuff...

               

              What I was expecting was a very smooth boundary edge (even on just one surface) when zooming in, but it still isn't perfectly smooth on the display. 

                • Re: Gaps between adjacent surfaces normal?
                  Andre Cardadeiro

                  Digging deeper, I went down to basics.  The rugged curve seems to come from Curve Projection -> Sketch on Sketch.  In other words, the two splines I draw are very smooth when zoomed in, but the projected curve which is based on those two sketches is rougher, almost as if I had dialed down the Image Quality setting in Solidworks. 

                   

                  I could not find any options to improve the quality of the projected curve, but this seems to be the first place where I see rough curves.

                    • Re: Gaps between adjacent surfaces normal?
                      Jerry Steiger

                      Andre,

                       

                      Some, probably a lot, of what you are seeing is just the way SolidWorks displays curves. The part that bothers me is that you see gaps after you Knit the surfaces. You are using the curve to generate both surfaces. Try using the edge of the first surface as the boundary of the second surface.

                       

                      Jerry S.

                        • Re: Gaps between adjacent surfaces normal?
                          Andre Cardadeiro

                          Jerry, after knitting, the gaps do disapear.   If I use the edge, I do not see the gaps.  They seem to appear after using a projected curve as an edge, which the projected curve itself is already less smooth than the original two splines used to generate it. 

                           

                          It seems in the end I'll just have to do one final Knit of all surfaces before exporting to STL to get rid of any solidworks-induced gaps.