Extract points from texture to mesh

Rhino Rhino for Windows
1

Hi all, is there a way to extract some points coordinates from a texture on a mesh?

I can explain more with an image:

sphere.jpg1445×866 621 KB

I have a sphere with a texture applied mapped in Maya, this texture has white background with some regular positioned black points.

Is there a way to convert this points in the 3D space and know the exact position?
I tried using the ApplyDisplacement command but with no success.

Thanks in advice, best regards,
Julio

2

It looks as though the dots are in a diamond shape and don’t pinch towards the poles. You could draw a simple grid using the radius of the sphere as a starting point and then scale it by a set amount to cover the points.

From there you can project onto the surface which would give you the result you want.

It might not be mm perfect but it’s a start - might be better to use the projected dots as the starting point and then apply a refined texture to match, if need be?

Andy

3

Hi Giulio - can you post that file and the texture?

-Pascal

4

Thanks for the reply, here’s the files: sphere.zip (1.2 MB)

Julio

5

Hi @Julio,

yes, but Rhino does not have the tools built in, some scripting is required to transfer the 2d point locations in the texture to 3d real points.

sphere.3dm (4.9 MB)

c.

6

Thanks @clement, that’s awesome!

I’m trying to figure out how you did it. Can you tell me how you unfolded the mesh?
Than I think you built the grid and positioned the points on it, and then you did the FlowAlongSrf command, right? I’m really courious about the steps you did.

Thanks again,

Julio

7

Hi @Julio

no, FlowAlongSrf works for surfaces only. To unwrap use _ExtractUVMesh, for the points transform I’ll send you an extracted snippet of code via PM as this is part of a larger project which is not ready for public yet.

c.