transform rotations of one object to another animating object normal

[rayt]

Hi,

 

I have run into an issue where I need to attach spheres to individual points on an animated surface. I can get the spheres to constrain to an individual point using a point expression in a transform node. However the spheres will not rotate as if fixed in place. The axis maintains its world position. How would I get the spheres constrained to the animated surface to rotate so Y (for example) is rotating along with the normal direction.

 

Any help would be appreciated.

 

Thanks,

Ray

[gui]

Add an "up" (vector attribute) to the geometry and use a copy sop to attach the geo.

At obj level, you can use the "rivet" obj to extract the transform.

[rayt]

Unfortunate a copy sop will not work. Each sphere is an individual element and must be animated by hand separately. Additionally, where would i be putting the up attribute and how would I implement it. There are multiple points to consider on the animated mesh.