David, Did you modify any of the Convert NURBS to Polygon Options? Use the option box for the command if you have and try different settings. It will take a little experimentation to get the hang of it. But I doubt that’s your problem.
So..... about Solids to Nurbs to Polys. This has always been a difficult process. Used to do a lot of this kind of stuff from ProE to Soft 3D. This is one of the areas though where Maya is well suited because it imports such a high number of CAD formats natively. The problem as you describe it is likely starting at the Solidworks side. Heres why: If you created the geometry as a solid, as with any application that generates these kind of objects, ProE, Solidworks, that kind of thing, Solids are not like Nurbs. They are mathematical representations which are geared towards creating watertight assemblies that can be sent to a 3D printer. There can be no unsealed objects in this path to the printer. The closest crude approximation or analogy I can give is that they are more similar to "booleaned" polygon primitives. But that is a severe oversimplification. When you convert a solid to Nurbs, the solids modeler has to figure out what to do with it. A solid of a sphere doesn’t translate to a nurbs sphere, so when you export it as IGES the software goes through all soft of machinations to try and figure out how to make b-spline surfaces out of it. Generally what happens most often, as was the case with ProE at least it would create surface approximations of a topology it could understand and then trim off the surfaces where they intersect. So for example, a solid sphere might get converted into 8 nurbs surfaces that are trimmed off to form 8 semi quadrants of the sphere. Not very efficient when in maya all we need is a single NURBS surface. Create any complex topology and it will just keep breaking it down further and further until it’s a shape it thinks is reasonable for a spline surface and then trim off any excesses. I converted a solids generated iges of an airplane once into Soft 3D this way it took several hours to load on a massive Onyx SGI. It contained thousands of surfaces and multiple trims per each surface. It was insane. Dependent upon the detail given to the original solid and whether its been shrinkwrapped or not, results will vary. But suffice it to say, solid to Nurbs to polys is not the best of paths. What you want to do is convert the solid to a mesh inside Solidworks. I don't know Solidworks so I am thinking you'll want to send an STL out of Solidworks. Look into "shrinkwrapping" it can also help the process. We used to have to do that in ProE, but don't know what its equivalent might be in SW. Then read the STL into Maya. There may be some cleanup but it should be mostly deleting stuff you don’t need and sealing edges where necessary. Generally an STL is a "poly mesh" but dependent upon the tolerances and granularity of the original solid they can be very course or very fine, think similar to render tesselation on NURBS, but for a "mesh" (not really a mesh, that’s why its called a solid). Once out of Solidworks though it can't be changed anymore so you have to manage the tolerances from the solids modeler side. After looking at what is currently supported I see Maya DirectConnect supports something called SW so I'm going to guess it might be able to read native Solidworks in directly? Never tried it so not sure but that would be worth a shot as well. Search Maya help for SW_DC. When dealing with a solid it always best to stay as close to the native formats as possible, but exporting as Nurbs (iges) from a solids modeler is not something I would recommend. -- Joey Ponthieux LaRC Information Technology Enhanced Services (LITES II) Science Systems and Applications Inc. (SSAI) NASA Langley Research Center __________________________________________________ Opinions stated here-in are strictly those of the author and do not represent the opinions of NASA or any other party. > -----Original Message----- > From: softimage-boun...@listproc.autodesk.com [mailto:softimage- > boun...@listproc.autodesk.com] On Behalf Of David Saber > Sent: Friday, January 29, 2016 4:45 AM > To: softimage@listproc.autodesk.com > Subject: Converting Nurbs to Polygons > > Hello list! > > I need to convert Solidworks IGES nurbs to polygons. > In Softimage, the IGES import fails and creates nothing more than a null. So > I'm testing Maya to achieve this. In Maya, the function is available in > Modify > > convert > nurbs to polygon. This works well, but I don't understand why the > resulting object has too many faces, has corrupted geometry and inverted > faces. Nurbs object are always simple, grid-like surfaces, that are just > given a > shape, so why aren't they translated into similar polygonal objects? > After this conversion, I export as FBX and import into Softimage where I > spend too much time cleaning the mesh. Is there a faster way to do this? > Thanks, > David
