I’m working on an arch visualization project. I’m exporting my surfaces as meshes in fbx file format so unreal engine can use them. I’m running into issue with Unreal Engine and nanite not being able to read the geometry because it is not a water-tight surface even though rhino says it’s a closed mesh. If I open the mesh in maya I can select all continuous faces of the mesh and is appears that they discontinue at edges which would mean the mesh is NOT closed… Is there a way in Rhino to make sure these meshes get exported closed to other visualization software can use them properly?
Maybe upload the surfaces in question as V7 or V8 file here, so people can take a look.
You could try _Weld, but be advised that hard edges like in your example in Rhino are always unwelded. You’ll find that when you weld the hard edges they are no longer hard in Rhino. That is because Rhino will be trying to smooth those. It is one of the drawbacks of Rhino meshes.
Below exported _MeshBox objects. The one on the right is just the original mesh box, the one on the left I used _Weld with angle tolerance over 90. Both I exported as OBJ, then imported in Blender. You see that the one on the left has smooth shading on the edges.
You’ll have to do the welding in your target software. In Blender I’d use Merge by Distance with Sharp Edges ticked for the one on the right. The one on the left is a bit more tricky, but Mesh > Normals > Average > Corner Angle followed by Edge > Set Sharpness by Angle will do the trick.
After said processes the mesh boxes have now both sharp edges, and have no disjoint mesh patches.
No idea how to do that in Maya.
In Maya, you first weld, then crease, then output as .fbx file or whatever. But since the OP does not want to upload the NURBS surfaces to be converted, one can only guess what’s wrong.
It isn’t hard to guess. Hard edges will be unwelded in Rhino, exported or otherwise.
As I said, you’ll have to do some extra processing in your target tool. Or if that doesn’t work in your tool of choice outside of Rhino.
