Re-mesh with keeping custom texture

[phillip]

There is a series of complex meshes with custom texture mapping. I´d like to remesh them with a higher density (ideally quad remeshing) but keep the original texture as close as possible. What would be the best way to achieve this without manually replacing every texture?

[martinsiegrist]

Rhino has a command called bakemapping but I’ve been struggling with it recently…

Modify UV mapping

Hi @martinsiegrist, You were really close, the issue was the custom mapping object not being directly over the source when that custom channel was created. I made a video covering the details here… BakeMapping in the Rhino 8 WIP - YouTube

Rhino 9 has some new grasshopper components in the rhino tab but some projection mappings aren’t available yet…

[phillip]

Hi Martin, thanks a lot for the hint. As I did some tests, I can understand what you mean by struggling. But it seems to be the way to go. Let me do some more test and come back with results. I will also look into RH9 gh as you mentioned, since it will be impossible to do by hand. If anyone knows some GH components that handle texture data really well, I am happy to hear.

[phillip]

Is there a way to extract the mapping data from this? I could not find any example files for the new components and I am not sure how to extract the texture color from a specific point on the mesh - In my case this would already be sufficent for what I want to do.
Or, ideally recreate the mapping in a similar way “BakeMapping” does.
Any ideas anyone?

[phillip]

This sort of worked, but is to tedious for a large number of meshes. I´d be also fine with just the color information which I could apply to the new mesh in my case.

[Holo]

To get this right on 3D scanned models would need to map the previous polygons that the new polygons of the reduced mesh lies above and then re render a new texture, one polygon at the time. It would be quite the undertaking, but should be possible with some clever thinking.

3D scanned models tend to have complex textures with bits and pieces all over the place, so figuring out a good unwrap process of the new mesh would be the first step to take.

Here’s an image of a model I scanned today with scaniverse on iphone 13pro (requires lidar)

And it’s texture:

(Resized from 8192x8192px to 1024 for size here on discourse)

[martinsiegrist]

I’ve done it two years ago but cant get it to work now

BakeMapping in the Rhino 8 WIP

[martinsiegrist]

Check the file in that post. The script extracts the mesh uv points.

Compute vertex colors in grasshopper

Thanks for the hints. Copilot wrote the python script. I modified it a bit and it works: import rhinoscriptsyntax as rs import Rhino def extract_uv_points(mesh): if not rs.IsMesh(mesh): return [] uv_points = [] for i in range(mesh.Vertices.Count): uv = mesh.TextureCoordinates[i] uv_points.append(Rhino.Geometry.Point3d(uv.X, uv.Y, 0)) return uv_points uv_points = extract_uv_points(mesh) [image] Wait Rhino 9 has a component calle…

[phillip]

Just what I wanted! Thanks!