[Bf-funboard] UV space constraint (stick on surface)

[Hadrien Brissaud]

Hi everyone,

every now and then people on ba.org are asking about ways to constrain a
object to a surface, like a shirt button, or any other prop you'd want to
stick to a deforming surface. Right now the best way I can think of is
parenting the object to a bone you've set up to follow the surface as
accurately as possible (along with shrinkwrap constraint, and so on), or
using the dorito method with the new depsgraph (
https://www.youtube.com/watch?v=SfgHAWTMLrE).
The first is a workaround that's difficult to make accurate while the
second depends on the new depsgraph being active, and as far as I know it
is note quite final.

In maya one would use hair follicles, which are stuck to the mesh in uv
space, and you'd constrain to one of these follicles whatever it is you
want to be stuck onto the surface. It is a very straightforward manner of
solving this problem and I think having a uv space constraint in blender as
a separate method would be cool, until the new depsgraph lands (I don't
know of an eta for this).

So that was just an idea. Obviously I does not work with overlapping uvs,
and it breaks if uvs change, but that's the toll. Thoughts ?

Hadrien