Hi maxim, so another way I could describe it is - if you want to transfer polygon mesh data out from MoI into a rendering program, then 3DM format is not a good way to do that. It's better to instead use OBJ format to transfer polygon data between programs, that's a much more common format to use for that particular kind of data.

MoI will only write NURBS data to 3DM files and does not store polygon data in them.

- Michael

Hi Maxim, also another reason why MoI does not try to store render mesh data in a 3DM file is that there are various limitations on it, like no n-gons, no ability to weld vertices but have distinct UV and normals for 2 faces that share a common vertex, and no way to have multiple materials on different faces within a single solid.

Using OBJ format does not have any of these limitations, that's another reason why it's better to send mesh data to a renderer by using OBJ format rather than attempting to store render mesh data inside a 3DM file.

- Michael

Hi Michael,
Hi Maxim,
As far as I can remember KeyShot(HyperShot) never really handle .3dm NURBS data very well it always relied on the mesh data in Rhino files.
Another good export option is STEP, I found KeyShot converts STEP data pretty good.

Cheers

Hi Danny - re: STEP - one issue with that is that material (style) assignments on different faces within the same solid will not go through with STEP, but it will with OBJ format. OBJ is just a more commonly used way to transfer render data...

- Michael

Hi Michael,

You're right about the individual faces you loose that with STEP or KeyShot used to, I haven't been keeping up with it lately so I don't know if anything has changed.
I mention STEP because of the two stage result; save as STEP, import into KeyShot, where as .obj is; save as, manipulate mesh, then import into KeyShot. I know some engineers that don't want to mess around with meshes, they just want a quick picture and KeySot's meshing of STEP files is pretty smooth.

Cheers