hi RMA team,
I went to export a SubD model from Rhino to keep working with it in Modo. The only way I know how to do this is _ExtractControlPolygon and export that as either OBJ or FBX. OBJ has been broken for a while and this week FBX broke too.
edit: running (7.0.20140.14505, 05/19/20)
Test cube file here:
My SubD object:
96 faces closed mesh:
3dm file here:
failing_export_mesh.3dm (296.4 KB)
I export to OBJ:
I get this mess in Modo (same mess in Fusion360):
single poly per cube face, and weird-ass normal map.
OBJ file here:
cube_mesh_symmetry.zip (928 Bytes)
which BTW I had to zip up because discourse does not support OBJ
I know OBJ has been broken so I have not been using it, but it wasn’t this broken, now it seems like a rogue file export that no one is watching or something.
I’ve been using FBX instead, but today I found this weird message, in V7:
Can you please give these issues priority and be part of a weekly build Q&A test before releasing a weekly build? We need file imports-export to work to do our work.
Hi Gustavo- if you un-check ‘Create NGons’ in the OBJ settings, does the export do what you expect?
for that particular cube yeah the problem goes away, by introducing another problem, look what happens with the Ngons in my file:
I export this (right cube has Ngons)
I get this in Modo:
I proposed a new setting for all mesh exports:
@tim - do you think it is possible to have a ‘Preserve nGons’ as well as ‘Create nGons’ check box?
@gustojunk - does this item correctly address the export problem for nGons?
RH-58695 Export : OBJ - Allow preserving existing nGons
Also what about solving those weird normal maps generated from extract control polygon. We do want good/usable normal maps. We don’t understand why _ExtractControl polygon is grabbing the normal maps from the smooth SubD. Any reason/utility on that?
@gustojunk - I think you mean that the vertex normals are welded on the extracted control polygon, correct? Not having those welded seems not to affect SubD creation (from them) in Rhino - if it is OK downstream as well (Unweld, 0 degrees to test) I imagine that can be fixed - I do not know if there is any particular need to weld these.
Hi Gustavo - can you please close Rhino, and run a repair on the WIP inastallation via the Windows control panel > Programs? Does that sort anything out for fbx?
Thank fixed it! Thanks!
I checked, Unwelded is a problem, look what happens when I import the unwelded version in Modo and switch between faceted/SubD:
So it looks like if you guys can fix the ‘ngons sometimes’ problem and we uncheck normal map when we export OBJ things come in well for Modo:
…also the subD control cage option allows me to skip the extract control polygon, that’s nice!
I just wish we had a better Rhino<>Modo link. I need to explore some other options.
RH-58695 is fixed in the latest WIP