Hi all,

This may be a super basic question but I'm struggling with it. To simplify, I have a torus that is rotating on one axis. I want a cube to sit on the side of the torus as the torus animates. I do not want to merge the objects and the objects will have different centroids so I cannot copy and paste the transform node with the animation. The full context is the torus would be a moving object (animation will be from an alembic) in the scene and the cube would be a particle emitter that needs to follow the animation of the torus.

How can I do this?

That's silly, just merge them. It's not like they can't be separated later by group.

Ah yeah, that makes sense in this simplfied version.

What could I do if the animated item coming is from and alembic that already has an animation and I want to attach an object to that animation?

harshmallow
What could I do if the animated item coming is from and alembic that already has an animation and I want to attach an object to that animation?

There's a few different options. if the animation is from a transform in the alembic, then it could be accessed directly by grabbing the packedfulltransform intrinsic matrix from the animated part. The object node alembic Xform could also be used.

For deforming animation, a rivet can be used but this requires unpacking and converting the geometry to polygons first.

Amazing, thanks for the info!