Volume mesh problem and radial edges

Dear all,

I’m facing an issue with volume mesh creation in Rhino using a griddle. See the attached images for clarity(Screenshot_18_01). The outer (black) mesh has an edge length of 1.5, the red is 1, and the blue is 0.5. The “volume mesh from griddle” command returns an error(see error_01). I’ve tried the Gheal command without success. Also, how can I make the corners of the blue mesh radial? Your help is appreciated.


Hi @Umer99,

have you tried to connect the gridpoints using Gint?
For rounded corners you would have to create a solid in rhino that contains them.


Hi @Umer99,

Nils is correct, your meshes are not conformal and they need to be intersected with GInt, then (ideally) remeshed with GSurf, and only then you would be able to create a volume mesh with GVol. This is a standard route when creating unstructured volume meshes.

However, I see that this geometry is relatively simple and if you are using FLAC3D, you could probably mesh this geometry directly in FLAC3D. If the blue and red regions extend all the way through the thickness of the model, you can use Sketch (in FLAC3D 9) or Extruder in earlier versions to create nice structured or unstructured meshes and then extrude them along the thickness. You could also use “zone densify” command for this type of mesh to create an octree-type mesh (similar to what you currently have in Rhino). But the advantage would be that you directly get an octree volume mesh in FLAC3D and you can attach all mismatching gridpoints/edges/faces. These two approaches might be faster than trying to build a good-quality unstructured mesh in Rhino-Griddle (at least for this geometry).

Thanks a lot for your reply.

Hi @apyatigorets ,

If I choose the same minimum edge length for the whole model, then it works perfectly fine, but when I choose a different minimum edge length for the inner section, it shows me an error in creating volume mesh. Yes, in FLAC3D9, it’s easy, but first I have to create the mesh for the model here, and then I have to create another model with the same geometry to check which one will be more efficient. I use the GInt command, but it’s not working for me as it creates a triangular-type mesh.

Hi Umer,
after using GInt, did you run the GSurf command as Apyatigorets suggested? Griddle Rhino Manual. It allows you to choose the kind of mesh (Tri/QuadDom/AllQuad). If you need a fully structured mesh, you should probably use Blockranger or FLAC3D as Apyatigorets suggested.

I would recommend that you read a bit through the manual and/or do the tutorials that you can find here (Griddle Manual & Tutorials) before you continue to build your meshes with Griddle/Blockranger.


@n.ehringhausen Thanks for your reply. Yes, I consider the suggestion of @apyatigorets, but I will check again.