Pure awesomeness

 From:  Michael Gibson
5880.11 In reply to 5880.10 
Hi Claas,

> The hand adjustment of the mesh can often fix some of the bad artifacts while this way
> maintaining also a less dense polygon mesh for rendering.
> However if time is an issue I tried out the edge settings and those problems often disappear
> once a certain mesh density is reached and the surface flow is amazing - just the file
> size increases.

If the proper vertex normals are used, it's a much different situation and even quite rough low polygon count meshes don't have these particular kinds of shading artifacts, then you only need to make heavier meshes to make silhouettes less pointy.

So again I really recommend using a renderer that supports vertex normals importing, which is basically any renderer at all except Blender currently. Hopefully Blender will be able to hit that target in their planned update, it will really make a significant difference in render quality when rendering CAD data.


> How complex is actually the math behind this? I can only imagine that this must be an
> incredible tough job to translate a NURBS data into a polygon mesh.

It's a quite complex overall process, especially with making things making things to be able to work with all kinds of geometry.

This one particular area of mesh generation is probably the single most time consuming individual feature area that exists in MoI, I'd say about 8 or 9 months of full time work has gone into just this one particular area alone. But it's resulted in a quite unique mesh generator, other NURBS meshers do not natively generate n-gons like MoI does and instead connect interior mesh vertices to edge boundary ones using triangles and it's easy for that triangle connection area to be kind of messy. Not just in topology but also in shape as well, like with Rhino the edges get meshed to certain tolerance settings, and the underlying surface gets subdivided to certain tolerance settings but then when the outer edge boundary vertices get connected to the interior "underlying surface" vertices, those connector triangles can cross too large of an area and form a kind of divot in the mesh , basically the triangle connection pieces easily go out of the tolerances that were used for other parts of the meshing, making a visible indentation in the mesh shape. There are quite a few people who use MoI just for mesh generation to go from other CAD programs into polygon data because of this.

- Michael

EDITED: 16 May 2013 by MICHAEL GIBSON