Hi Gep - sorry I'm not completely familiar with some Modo details - how is it that using double-sided materials does not allow you to select the polygons?

Do you mean you are not seeing the back-facing polygons inside of the Modo editor window? Surely there is some setting within Modo that you can toggle to make those show up and be selectable. You may need to post a question regarding that in the Luxology forum to get some modo-specific advice for that part.

> As for the creases on n-gons, here is a picture (i turned on
> reflexion mode in viewport for better visualisation, these
> creases do show in render) :

Are you 100% certain that you have the vertex normal map being used in that case? Getting the proper vertex normals to be used should avoid shading glitches like that from happening.

Also which format did you use for transferring - you should usually use LWO format to get the best results with going to Modo.

If you still can't get the n-gons to shade properly even if you're really sure you're using the vertex normal map, can you please post a 3DM file with that geometry in it that you are showing there (just only that geometry and not all the rest of the file would be easiest to test with), so I can take a look at it?

Also note that if you want to have a solid but have the pieces for it to be separated on export, there is actually a setting for "Weld vertices along edges" which you can uncheck when exporting solids out from MoI which will make the mesh generated from each surface in a solid have its own separate vertices along shared edges (but with still unified mesh structures) instead of having faces actually share a single vertex in common between them where they touch at a common edge. So if you want to have separate pieces in Modo it's probably best to keep things as solids but turn off welding at export time to get that, sorry I forgot to mention that setting previously.

But I'm kind of confused about that screenshot that you show, because that's exactly the kind of artifacts that you should not be seeing if you get the vertex normals that are exported from MoI to be used for the rendering. That screenshot looks like the kind of thing you would see if you are not using vertex normals from MoI and instead having Modo automatically cook them up by just averaging the normals of adjacent faces - that's what happens if the vertex normal map is not used.

- Michael