a bit ago i remade primuv() in opencl, and today I remade xyzdist() too. in case it helps anyone: github.com/MysteryPancake/Houdini-Fun/blob/main/Primuv_Xyzdist.md
xyzdist() requires a primnum unlike the regular version. it returns the nearest surface position and uvw coords the primnum can be grabbed from a point cloud or something else supporting BVH acceleration