Hi Shaun,

> While the rendering may be capable, it seems there are issues importing MoI OBJ
> files. If you get over that hurtle the best renderer may be a free one…

Actually the issue is that Blender doesn't do very well with importing OBJ files from any CAD program, not just something specific to MoI in particular.

The problem is that they just ignore the "vertex normals" information in the OBJ file - that data in the OBJ file is not read in, and there are also various other problems with vertex normal handling in Blender as well like even if they are read in they get discarded at render time.

See here for some previous discussions on this:

http://moi3d.com/forum/index.php?webtag=MOI&msg=5083.6
http://moi3d.com/forum/index.php?webtag=MOI&msg=4515.3
http://moi3d.com/forum/index.php?webtag=MOI&msg=4272.1
http://moi3d.com/forum/index.php?webtag=MOI&msg=4409.79


The omission of vertex normals import makes it pretty difficult to get high quality renders of CAD data in Blender. Every other rendering program that I'm aware of does not have this particular problem, but it has been an issue with Blender for a really long time now.

So if you need to render CAD-generated polygon data such as the data exported from MoI, Blender does not really work particularly well for that right now because of this particular limitation in it. You can get the raw polygon data into it but when the polys are shaded you will likely have various kinds of shading artifacts that sort of "leak" some resemblance of the polygon structure into the rendered result. Those kinds of artifacts do not happen at all when the vertex normal data that's included in the OBJ file is used for doing the shading, so you really want to use a renderer that is able to import and use that data instead of ignoring it.

- Michael