Can you reduce the faces of a T-Spline

[Anonymous]

Is there a method to reduce (or merge) the faces of a T-spline?

I have a model that started as an STL mesh with 300k+ faces, I have reduced them down, then converted to quad-based, then converted to a T-Spline so now it is a solid. However, it still has around 300 faces. My issue is that this is going into ABAQUS for FEA so ideally I need to be able to import it with less than 50 faces otherwise my model will be far too complicated.

All ideas/help is appreciated. I feel like I've tried everything I can think of (including other software) and I have had no success.

[Anonymous]

Is there a method to reduce (or merge) the faces of a T-spline?

I have a model that started as an STL mesh with 300k+ faces, I have reduced them down, then converted to quad-based, then converted to a T-Spline so now it is a solid. However, it still has around 300 faces. My issue is that this is going into ABAQUS for FEA so ideally I need to be able to import it with less than 50 faces otherwise my model will be far too complicated.

All ideas/help is appreciated. I feel like I've tried everything I can think of (including other software) and I have had no success.

[adam.helps]

Realistically you're not going to go from 300,000 faces to 50 faces by removing topology. If you just needed to shave off a few faces here and there, removing edge loops might be viable, but I don't think that's going to be good enough.

However, since it's only about fifty faces, you can probably create the topology from scratch using the face tool. The idea is to manually draw a fifty-face model on top of your original, using its shape as a reference. You can improve the accuracy using a combination of face's object snap, the pull command, and manual adjustment.

See https://knowledge.autodesk.com/support/fusion-360/learn-explore/caas/screencast/Main/Details/56bbc0e... for an example workflow that sounds similar to what you need.

By the way, it's not totally clear from your problem description whether you're worried about the total number of T-Spline faces, or just the total number of faces on the body you end up with after you hit "finish form." If you're mostly worried about the final body, the main trick is to keep the number of star points low. Manually rebuilding the shape is still perhaps the right answer, but make sure you pay attention to how many star points you have; the more you have, the more faces the final body is going to have.

[adam.helps]

Realistically you're not going to go from 300,000 faces to 50 faces by removing topology. If you just needed to shave off a few faces here and there, removing edge loops might be viable, but I don't think that's going to be good enough.

However, since it's only about fifty faces, you can probably create the topology from scratch using the face tool. The idea is to manually draw a fifty-face model on top of your original, using its shape as a reference. You can improve the accuracy using a combination of face's object snap, the pull command, and manual adjustment.

See https://knowledge.autodesk.com/support/fusion-360/learn-explore/caas/screencast/Main/Details/56bbc0e... for an example workflow that sounds similar to what you need.

By the way, it's not totally clear from your problem description whether you're worried about the total number of T-Spline faces, or just the total number of faces on the body you end up with after you hit "finish form." If you're mostly worried about the final body, the main trick is to keep the number of star points low. Manually rebuilding the shape is still perhaps the right answer, but make sure you pay attention to how many star points you have; the more you have, the more faces the final body is going to have.

[TrippyLighting]

Even if you model is only going to have 50 faces it might be far too complicated.

Have you ever taken a NURBS surface created by a T-Spline and looked at it in another  CAD software - Autodesk Alias, for example - which allows you to look at the CV distribution and density (CV - NURSB control vertices) ?

Even a 50 face body might have a NURBS surface with a very dense CV mesh.

Also, what FEM accuracy are you expecting form a model that has already lost its original topology and accuracy when it was converted into a triangulated .mesh with a finite resolution  and then gone through another conversion into a T-Spline based NURBS surfaces and then will go through another meshing stage during the FEM analysis ?

[TrippyLighting]

Even if you model is only going to have 50 faces it might be far too complicated.

Have you ever taken a NURBS surface created by a T-Spline and looked at it in another  CAD software - Autodesk Alias, for example - which allows you to look at the CV distribution and density (CV - NURSB control vertices) ?

Even a 50 face body might have a NURBS surface with a very dense CV mesh.

Also, what FEM accuracy are you expecting form a model that has already lost its original topology and accuracy when it was converted into a triangulated .mesh with a finite resolution  and then gone through another conversion into a T-Spline based NURBS surfaces and then will go through another meshing stage during the FEM analysis ?