Constrain mesh to an imported alembic cache surface

[Anonymous]

Hi All,

I have a scene with an animated surface (1) that was imported as alembic cache. 
I'm trying to connect a different mesh(2) to one of it faces using the "point on poly"(3) constrain, however, it doesn't work.

I also tried to connect a curve to it, using the nconstraint, "point to surface", during an nHair simulation and it didn't stick as well.

Can anybody help? 

Thanks,

Ofir

[mspeer]

Hi!

"...it doesn't work."

- What does this mean?

What are you doing (step by step), what happens?

[Anonymous]

Hi, thank you for replying!

I'm trying to make the mesh (2) to move with the surface (1).  

So I selected the face from the surface, added the mesh (with shift), and then choose the "point on poly" constrain.  

Although the surface is animated, the mesh doesn't move and I think it related to the fact that the surface was imported to the scene as alembic cache (it works just fine if I connect the mesh(1) to an animated box).

Is there a way to make it work?

Thanks!

[mspeer · Accepted solution]

Hi!

Do you have UVs on your alembic mesh?

UVs are required for the constraint.

[Anonymous]

Thanks a lot! 

Indeed that was the problem.

I have one more question, when I applied a UV map on the surface I was able to connect the mash to it, but the objects now jump all over the place when I play forward, like this:

Is it because I applied UVs on an animated surface and not the other way around?

(I already recreated the scene, but I'm still wondering what was the exact problem) 

[mspeer]

Hi!

"Is it because I applied UVs on an animated surface and not the other way around?"

- Yes, that's very likely the issue here.

If the UV map changes during animation it will not work.