Point Group From Texture

[Three65]

I am trying to do a vellum simulation and was wondering if its possible to select points and group them based off a texture map. What I would like to do is build a UV for the model I am using and then just use a black and white map maybe to select points based off the map. My issue is that I am Remeshing my object on import and have to keep adjusting the remesh to get the right amount of points for my simulation. However the shape never changes so if I could use a texture map to select the points I need every time I remesh it would save me from having to re-select them. Hopefully this makes sense.

[davpe]

hi, that should be fairly easy.

on your original geometry with uvs, use "Atrribute from map" SOP - that will do like a point colors, based on the uv mapped texture you bring in (so the geometry resolution plays a role here).

then attribute transfer the point colors to your remeshed geometry (attribute transfer SOP) - this expects the gemetry shape is not changing much as you suggested, otherwise the workflow would be a bit different.

then on your remeshed geometry use a point wrangle with a code like this:

if(@Cd.r>0.5) @group_mask = 1; 

and that will do a group called "mask" where the map intensity is more than 0.5 (borrowing a red channel here but it doesn't make a difference with grayscale maps).

and that's it.

cheers. D.

Edited May 1, 2020 by davpe

[Three65]

I will give this a try davpe, thanks for taking the time to reply to this. I have been doing some research on transferring textures to points and grouping by color. This will help out a lot and save me a bunch of time. Thanks Again I appreciate it.