How to split or 3d aerial mesh

Rendering
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Hi all, I have downloaded a 3d aerial model (attached). I would like to know how to cut out a portion of the mesh so I can insert a model of a new building to replace an old one. I have tried the mesh boolean split and mesh boolean difference tools and these works but they completely stuffed up the aerial imagery. It started projecting onto the cube I used to split the mesh with. Anyone know a work around for this? Cheers

Tile_+023_+029.fbx (17.4 MB)

Tile_+023_+029_0
Tile_+023_+029_01920Ă—1920 836 KB

Tile_+023_+029_1
Tile_+023_+029_11920Ă—960 389 KB

1 Like
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Hi @Louis9 ,

Can you post the texture map for this file? There are two meshes in it and two image textures missing.

4

Hi Brian,

Are they not the two jpegs also attached in my post? In the folder I received, the file and those two JPEGS so assumed it was those. Can try a different file if those aren’t working for you.

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Hi @Louis9 ,

My mistake, yes that is what I needed, thought it was a screenshot. Draw a Polyline and use the command MeshSplit and it should work for you…

image
image1044Ă—1096 159 KB

There are two meshes in the file which you’ll have to split separately to delete those areas.

In what will be the next service release candidate of Rhino 8 (8.12) we also fixed an issue that will allow you to Join the meshes first and do one split but for now you’ll need to do it twice.

1 Like
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Great thanks works perfectly cheers

1 Like
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Hi @BrianJ

This has been working well lately but I wanted to know if its possible to do on larger meshes. I have a project with a very large mesh (unsure to find out how many faces its made up of but when I ran meshrepair it says Mesh has 32868 degenerate faces, 172834 non manifold edges.
and 36738 duplicate faces). I hope that gives some sense of the scale.

When I try currently, the process gets to about 84% then gets stuck there for hours. I notice when I do this on smaller meshes it goes from being one big mesh to lots of smaller pieces, I assume that process is the reason why its not working when I try on larger meshes.

The only solution I can think of is to break up the mesh into smaller sections in blender and reimport them and run that process but would be preferable to do all in Rhino if you know a solution. Worth noting that this mesh is purely for visualiation so I don’t care if the meshes aren’t perfect etc.

Thanks,
Louis

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Hi Louis,

It’s hard to say without seeing the large mesh in question along with the cutting object used in MeshSplit. In general, it sounds like the location for the split is hitting one of the issues reported in the mesh. You could try moving the cutting object slightly or splitting the mesh into a few larger sections first to figure out what part is causing the delay.

If you use Rhino Accounts and send the mesh with the cutting object to my attention, I will take a look as well.