Converting stl with tet mesh into quad mesh stl

Hi Everyone! I’m trying to use Rhino to covert stl file with tet surface mesh and covert it to quad mesh. My final aim is to use this object in ABAQUS for structural analysis. But I’m getting multiple errors while trying this. I’m new at Rhino so I’m not able to figure out how to resolve this. I would like to hear some recommendations from the community if anyone has tried it before.

GUC_RD50.stl (971.4 KB)

This is the initial stl file I wish to work on.

Hello - what is the error message(s) exactly?


Mesh has 9 pairs of faces that intersect each other.
Mesh has 8 naked edges. Naked edges can cause problems if the ultimate goal is STL output.
I’m trying to check for naked edges but I do not wish to work on each edge manually since this is my initial structure and I wish to work on more complex structures later.
Attaching the reference picture.

Hello - I set a target edge elngth of .3334 (similar to the triangles) and got a clean meah from QuadRemesh - try that. - at about 30 degrees for the planariy setting.
QuadrangulateMesh amy also be OK here

Using 0.3334 edge length I’m getting following errors.

Mesh has 1 non manifold edge.
Mesh has 1 duplicate face.
Skipping face direction check because of positive non manifold edge count.
Mesh has 5 pairs of faces that intersect each other.
This can cause problems if you’re doing mesh boolean operations with it.

Mesh has 1 face where the face normal differs substantially from the vertex normals.
These normals can cause problems if the ultimate goal is for rendering or boolean purposes.

I also tried using the python script in one of the threads;

But I’m getting Out of Index Range error on running this script on my quad mesh.

You can try using the MeshSelfIntersect command.
The script you talk about works in rhino 6 and doesn’t find the overlaps.

Hi -
So far, you have only expressed a requirement for the outcome to be a good mesh. I’m not sure if that means that you are good with the overall shape of the resulting QuadRemeshed mesh.
If you are good with that, I find that first sending the mesh through the Grasshopper TriRemesh component, and, then through QuadRemesh gives a good mesh.

In the attached, I have put the “length” slider at 1.2 so that it doesn’t take a very long time when you open the file. The internalized preview mesh was made with that slider at 0.2.
Convert to (3.4 MB)