Hello Michael,
Thank you for your reply addressing all of my points and for taking so much time to answer everyone's questions and especially with my walls of text.
1. Hopefully yes but I don't know much right now about what will be the focus areas for MoI v5 so I'm not able to make any promises right now about what will be done for v5.
A: Thank you! Will upgrade to 4.0 as soon as the release version is out and then hold on tight for 5.0. Can we get staggered releases for 5.0 for Windows and MacOS, if 5.0 is ready for one OS earlier than the other? Also, if you perform improvements on importing in 5.0, can you please keep my step files on hand to test with as well?
2. There have been improvements to importing in every release of MoI though, so it would be pretty unusual if there weren't any for v5 as well. I have a general sense that the most problematic area for imports is in dealing with closed surfaces so it is possible that some attention to that particular area may yield a good improvement.
A: The models I import to MOI are solids only, so closed surfaces.
3. That would be .3dm import, it's the closest to how MoI represents models internally and so involves the least amount of processing and manipulation of trimming boundaries.
A: Thank you. I downloaded the trial version of CAD Exchanger and was able to convert the mould model to .3dm with that but it still did not import correctly in MOI 3.0. I've attached it. So I guess I'll need to hang on tight for 5.0 for exporting some of my CAD models to .obj.
4. The file import process uses 64-bit double precision floating point values throughout and so it can't be this problem either. MoI already uses double precision floating point for all geometry processing, single precision is only used in the display engine when sending display data to the video card.
A: Thank you, that's very impressive.
5. The square plug is coming from the "underlying surface", the plane surface that is underneath the trim curves. If you delete it then you can use the show naked edges scripts from the link above to see where the really skinny piece is at:
A: Thank you. I was able to more clearly see and find the surface by cutting the model in half after importing it in MOI. I highlighted a surface behind the actual problem surface so that it's easier to see in this screenshot :
Sometimes import issues occur with curved surfaces rather than flat ones, which is a challenge for me to correct in MOI, especially since I'm used to working only with solids.
5. Are you seeing these seams only with MeshMixer or are you also seeing them in other programs as well?
A: In the past, I used to also be able to highlight these with Meshlab 32 bit, on an older PC. But the latest version of Meshlab 64 bit no longer seems to offer that functionality. I've not yet found any other software that can highlight non-manifold edges to corroborate the issue. So I cannot check whether it's just Meshmixer showing thin triangles as actual cuts or seams in the mesh.
6. It looks like it's probably an issue specific to MeshMixer where it is not liking to combine very skinny triangles. You could try adjusting your meshing settings on export to reduce the formation of long skinny triangles, the "Divide larger than" setting can help with that:
A: I'm not using Mesh Mixer to combine vertices or perform any changes to the mesh at all. I only use Meshmixer to inspect the meshes of .obj files exported from MOI, to see where the mesh is separated into distinct triangle islands due to vertex duplication by highlighting seams which should be the edges of mesh islands. However, I could see how it may be possible for the way Meshmixer highlights seams to also highlight very very close edges of the same triangle even though those aren't actually cuts/seams in the mesh.
If that's the case then I consider the issue resolved or a non-issue to begin with. Unfortunately, I cannot check and confirm that it's Meshmixer misrepresenting the edges of very thin triangles as a seam or cut in the mesh.
If you can confirm that those redundant seams that got highlighted in MeshMixer (and which I highlighted with red in the screenshots) aren't actually cuts/seams in the mesh and are instead misrepresented as such by Mexhmixer then that would give me peace of mind as this is the only other issue I have with MOI currently, besides importing some models from CAD.
I only used the 'Divide Larger than' on curved surfaces because it made no sense to also use on flat surfaces as well as it would just inflate the poly count needlessly. Moreover, the flat surfaces that neighbour curved surfaces seem to get extra triangles as well, so that their vertices match up to those of their neighbouring curved surfaces even if their corresponding mesh islands aren't actually connected. So I hadn't thought about dividing flat surfaces as well.
My only concern is whether or not additional seams shown by MeshMixer are indeed extra cuts in the mesh. If that's not the case then exported meshes containing thin or small triangles is certainly not an issue.
Thank you for al the time you take to look into and answer questions and even help with models!
Best regards!
