I wanted to share some work I've been doing recently with this function in Shark. Unfortunately we have lost the function in V11, but if you still have V10 you can use it.

So a while ago I brought in a mesh, scanned data, used the convert to quads thing, worked OK, still a bunch of triangles then tried the mesh to nurb. Waited a loooooooooooonnnnnggggggg time for nothing to happen. I then started bringing in quad meshes still waited a loooooooong time for nothing to happen.
So recently I experimented. I used a program called instant meshes that reorders your mesh in quads. It's advertised to convert high poly to low, but you can ramp up the vertex count and get a dam good mesh from it. So what happens? Instead of the mesh being a bit all over the place, this recorders so its all nice and tidy, and guess what? Mesh to nurbs finds it and converts it a whole load better, faster and with less mess.

So the moral of the story, get a nice mesh. You may think this is blinding obvious, but not all meshes are nice, and ordered nicely from top to bottom. And would you think of this first time round? Probably not.

Anyway those who are still awake after reading this far, try it and see what you think.

Yeah I tried a mesh out of topogun, and the results are good as well. Want to experiment and try to figure out what makes a single surface, so the nurb might be made up from a number of surfaces, I don't like lines :-) :-)

PowerPack works great with a low poly quad mesh. This is similar to a subdivision in a regular 3D editor. A higher number of polygons gives worse results. Often the surface is uneven and bumpy.

InatantMesh will not give a mirror-smooth surface, but it is quite suitable for organic matter.

I was completely struck by this 3DMax's plugin. It creates a great NURBS from scanned mesh. WOW! https://youtu.be/INIzKLmvLsI

mesh to nurbs works really, really well from subD models built within Shark/VC. The issues that we have with imported meshes is the conversion from triangular faces to quads. I've also had better results from splitting models into mesh surfaces and converting the surfaces independently. That 3DS MAX plugin is the same IntegrityWare libraries as PPP's. Promo videos show products at their best, naturally. Tim's got a video with a hippopotamus model that's similarly impressive in conversion.

Using mesh to analytic for mesh models, a plane would ideally have zero deviation, cylindrical surfaces differ between internal and external: internal cylindrical surfaces (holes) should be the largest diameter that'll pass between the facets, which implies that the measurement is a three-point circle taken from the mid-point of the facet edges, ie a circle within a circumscribed figure. External cylinders will be a diameter taken through the end points of the facet edges, an inscribed figure. The reasoning is that holes are sized for clearance, external radii will usually be fillets and refer to adjacent blended faces. Mesh to nurbs is much more vague. This pic is of a car's windscreen manually reverse engineered from an .stl, and it's displayed in Shark and in Marcus Bole's PolyCAD. Should the facets of an .stl be drawn between vertexes that lie on the surface, or does the centre point of the triangle lie on the surface, with the vertexes outside of the hull?

Edited by user Sunday, March 3, 2019 6:33:52 AM(UTC)  | Reason: Not specified