Help! Trying to cut out 3D mesh using mesh trim


I am trying to cut out a 3D mesh of a lattice structure using the “mesh trim” tool. My end goal is to have cut out a 3D mesh in the shape of a cylindrical disk with a defined diameter and thickness. I have attached my Rhino 3D model. I have tried to setup a 2d circle curve but not sure how to setup it up properly. I am curious what would be the best method to achieving this?


Lattice Structure.3dm (899.0 KB)

I tried MeshBooleanDifference with your mesh and a disk-like extrusion and it works well. :slight_smile:

Oh perfect! I gave it a try and was able to get a similar result. Thanks so much!

Hi ferry59,

I was attempting to use MeshBooleanDifference again and I seem to be running into issues with my resulting mesh. For some reason the object is not a complete solid, like it’s giving me the opposite result I desire compared to your shared image. Do you have any tips or general steps I should follow to ensure I get the right 3D mesh cut? I attached my slightly modified mesh/model again. Lattice_updated.3dm (1.0 MB)


Hi Daniel,
no Problem here, file is attached, witch Rhino version are you working with?


Lattice_updated.3dm (1.1 MB)

Thanks Ferry, appreciate it! I am using Rhino 7.

One thing I notice is whenever I’m trying to do a solid cylinder it doesn’t create a solid texture like on yours. Is this a version difference?
Screenshot 2021-08-19 095041

Try extrude handle nr. 13 on a circle, select the surface, then type cap :slight_smile:

Hi ferry,

Hope you are doing well. Sorry for the late reply but I eventually was able to get meshbooleandifference to work using the gumball tool, cap, and steps involving the solid part and mesh with my lattices.

This time I modified my lattice structure features and attempted the same exact steps. Frustratingly, meshbooleandifference is not giving me the inner features. I attached my new file with a similar shaped lattice with the results I got. Would you happen to have any tips or check if the method work on your end so I’m not going crazy? :sweat_smile:

Also for some reason I get inconsistent results with meshbooleandifference sometimes where I have to make copies of the solid or mesh for it to work. Have you encountered this as well?

Thank you!
Daniel (9.2 MB)

Hi Daniel,
there are many reasons why boolean-operations fail. So far I could use MeshBooleanIntersection successfully, didn’t try others because as you know: this takes time…
Search in this forum, there are many topics about this and many tipps from people more with a lot of experience.
One little hint maybe: The polysrf in your file tries to cut the mesh exactly at top and bottom where many mesh-edges are settled on. BUT: maybe not exactly - maybe their z-values differ a tiny little bit, smaller then can be computed. So moving the polysrf for about 0.1 units might improve the results.
Good luck

Thank you for you quick reply ferry! I really appreciate you helping me out in the initial stages. I’ll go about asking others on this forum and see what their opinions are on the matter.