regart

Hi everyone,

I am looking for a robust workflow to create Vellum Stitch Constraints based on an explicit ID attribute (or a list), rather than relying on the standard proximity search (nearpoint/maxdist) of the Stitch Constraint SOP.

I have a cloth mesh and a target geometry that are initially far apart. I want to stitch specific points on the cloth to specific points on the target based on a matching attribute (e.g., i@target_id), regardless of their distance in 3D space.

With VEX I tried to build the constraints manually, by creating the polylines connecting the source points to the target points and set the necessary attributes like, type, restlength, stiffness etc.
But I am struggling to inject these custom constraints into the Vellum stream correctly. When I try to feed them into the Vellum Solver, the geometry disappears. Probably because of a point mismatch.

My Questions:

Is there a "clean" way to tell the standard Vellum Stitch Constraint SOP to use an attribute lookup instead of spatial proximity?

If I build the constraints manually via VEX: What is the correct topological workflow to merge these new polylines back into the Vellum stream? Can I make use of the vellum pack node somehow?

viklc

regart
I get a -1 as a value instead of the actual string value.

Not sure but it could be a bug. I remember facing the same issue some time ago since then I use string parms as menus to pass string values.

Thank you! By using string parms, it works!

Thanks for your replies!

I tried


instead of


this didn't seem to change anything. The dropdown menu works, just like before. Meaning the string values from the array are listed as expected.

Also I made sure the the attribute didn't exist in the first place.

But still, when I try to access the parm with vex from the wrangle, I get a -1 as a result.