14 Replies Latest reply on Jun 6, 2013 9:00 PM by Jeremy Savage

    Fading Surface

    Jeremy Savage

      Hi guys,

       

      I am trying to create a cut in a complex surface. I would like the surface to be tangent on one side (A) and indented on the other (B).

       

      surface1.jpg

       

      Would you use a boundary surface to accomplish this? I tried a few different variations but didnt have any luck.

        • Re: Fading Surface
          Anna Wood

          This blog post by Matt Lombard may be of use.  He discusses fades.

           

          http://www.dezignstuff.com/blog/?p=785

           

          Cheers,

           

          Anna

            • Re: Fading Surface
              Jeremy Savage

              Thanks for the link, it looks promising. 

                • Re: Fading Surface
                  Matthew Perez

                  Jeremy, i typed a long response but i messed something up and lost it:)

                   

                  The first issue i saw with your file is that your guide curve doesnt intersect the left side of you opening(the tangent side).  You need to Pierce there as well as make your guide curve tangent with the surface.  I like to use the "convert entities" drop down and use "intersection curve".  this will create a curve where your sketch plane intersect the surface.

                   

                  The main issues with this method are really in knowing what your end goal is.  I uploaded a version of this for you to see but its not the way i would approach this.  I would make a boundary surface of the "bottom" of the indent and then go back and fill in the edges.  This would let me have a much greater control over the curvature and the geometry.

                   

                  what is your end goal for this?

                    • Re: Fading Surface
                      Jeremy Savage

                      Thanks Matt, Your method really helped! I was trying some methods from http://www.dezignstuff.com/blog/?p=785 but couldnt get any to work.  The end goal is a model for renders and to talk with vendors. 

                       

                      I think the method you attached will work for what I need,  but I would like to try the additional approach you talked about. I am trying to understand how its different than the attached model? It seems like for the attached model you made the bottom surface and filled it in. Maybe you wouldnt have the bottom boundary surface attach to the deeper side?

                        • Re: Fading Surface
                          Matthew Perez

                          attached is a quick example.  Your geometry doesnt work easily and would need some more time.  Specifically the smaller radius cut at the top right of the opening produces issues with geometry that would need more time to sort out.  Basically I created the "bottom" face of the pocket and then worked on creating the walls that blend in.  I don't like using fillets in SW for surfacing because they are constant radius.  If I were producing something like this i would be defining the 'rounds' on the blends in a few sketch profiles using conics so i could better define them duing the surface creation.  I would love to work up a more detailed example for you but unfortunately i am up against some deadlines that i need to be working on. 

                           

                          Let me know if the process at least makes sense.

                           

                          I believe you can download the models from Matt Lombards blog and take a look at them right?  I haven't done this but that might also provide some insight.

                            • Re: Fading Surface
                              Jeremy Savage

                              Thanks Matt, I think I see where you are going. Is there a way to increase the blend size on the top edge? The bottom edge is blending nicely but the top is sharp. 

                               

                              Matthew Perez wrote:

                               

                              If I were producing something like this i would be defining the 'rounds' on the blends in a few sketch profiles using conics so i could better define them duing the surface creation. 

                              I am interested to see how your above comment would be executed. If its not to much trouble could you provide an example?, ( after your deadline )

                               

                              I was able to download a few of the models on Matt Lombards blog, I used them as examples but couldnt get it to work correctly. So far your example has produced the best results.

                                • Re: Fading Surface
                                  Matthew Perez

                                  ill try when i have the time.  When you say top edge can you take some screen shots and just give me an idea of the final shape you want.  Do you want it to be more like your attempt?

                                    • Re: Fading Surface
                                      Jeremy Savage

                                      The edge I am trying to achieve is close to what I have. I was wondering if I was making it the correct way, and am interested to see how you would make it.  I would like to be able to adjust the curvature between the top edge and the inner wall for future modifications.

                                       

                                      I couldnt figure out how to controll the curvature where the 2 surfaces come together on the top edge in your version. I was trying to make them smoother like mine below.

                                       

                                      top edge - perez.jpg

                                       

                                       

                                       

                                      My attempt:

                                      js surface a.JPG

                                      js surface c.jpg

                                       

                                       

                                       

                                        • Re: Fading Surface
                                          Matthew Perez

                                          Jeremy, the surface is weird in that corner because there is a tight radius as mentioned in my previous posts.  Ill try to tweak it while i have a simulation running and upload another version. 

                                            • Re: Fading Surface
                                              Matthew Perez

                                              Jeremy, i didnt have time to do up the model like i wanted.  My simulations ran fast which isnt a bad problem to have.  Anyways maybe i can answer your question though.

                                               

                                              To control the curvature on the upper edge you will want that lower pocket surface to be farther away from the edge.  So far the examples i made for you i pretty much drove the shape with the "weight" inside the boundary surface.  In the attached example I went ahead and made boundary surface 20 which is driven by a spline inside sketch25.  If you have a specific "blend" you want it will be best to drive it with a sketch like i did, and then let that blend out into the other areas.  The reason I said your shape was causing trouble is because blending like this where there isnt much definition, but going into a tight radius like you have in the upper right hand corner of the opening, gives you some less than ideal surfaces.  I was hoping to have the time to show you this but in the mean time maybe you can work off what i did on the attached file.