Mesh Difference Failure

Hi Guys

I have problems to get Mesh Difference operations done in Grasshopper

I have also tried solid difference operations and Mesh split.

But none of them seemed to work.

Has anyone successfully managed to make these operations?

Do you know alternatives to Rhino for Boolean operations?

I am using Rhino 6…

ThanksMesh Difference Failure.3dm (136.2 KB) 19.07.24_Split (28.2 KB)

Befriend yourself with @Terry_Chappell. He’s The Mesh Split expert.

// Rolf

I looked at your Mesh_Difference_Failure but cannot make sense of it. Can you provide:

  1. The starting mesh
  2. Details on how you want to split or trim the mesh.

With this I could try to split it with my Python script.

I do not use Grasshopper so I did not look at the .gh file.


HI Terry and RIL

Thanks for your replys.

Mesh Split.3dm (893.7 KB)

At the beginning i had open meshes (on the layer: “original open mesh objects”)
I wanted to close all the open meshes using grasshopper but i did not succeed.
So after half a year of trying, i put it to Microsoft 3d Builder which closed all the open meshes but also combined them to larger meshes.
The result is on the layer: “objects from 3d builder to be split”

Now i want to split these buildings into smaller parts again for my urban analysis.
Therefore i generated Splitting objects.
I put these splitting objects on the layer: “splitting objects”

When i try to do a Mesh split it always fails in parts.

Best thing would be to just close the “original open mesh objects” without combining them like 3d builder does.

I want to do some volume analysis therefor they need to be closed

I am thankful for every hint.



I looked at your Mesh_Split.3dm file and see something like this for the simplest part with only the original open mesh objects turned on:

The mesh in this area is actually consists of 4 meshes. Do you want to split them using the grey-colored walls in this view?

I am pretty lost in trying to figure out what you need.


Hi Terry

I either want the open meshes from the layer :“original open mesh objects” to be closed


I want the objects on the layer: “objects from 3d builder to be split” to be split by the objects on layer:“splitting objects”

can you do any of that?

Thank you very much and sorry for the confusion.

If I understand you correctly, you want the 3 starting meshes cut by the polysurfaces as shown in this top view:

I notice the polysurfaces have thickness. Do you want to remove a slot the width of the polysurface from the mesh, or do you want to use the center line of the polysurface to cut the mesh?


Hi Terry

Yes thats right.
Both options would be fine for me.
If you dont need a Volume and could cut it with the center line it is even better.

Thank you


I am still looking into this. I have been busy finishing up work for another forum member struggling with reading point clouds. I now have this squared and will begin looking at your example again.