Baking UVWs

[spacematt]

Hi there, in a different thread about 3D procedural textures on animated objects, there is this comment...

Normally you do this by baking the object-space UVW coordinates into a color channel for the mesh, and then use those to drive the procedural texture.

It makes perfect sense, but can anyone advise how to do this? I can bake the UWVs into EXRs easy enough, but piping the resulting RGB from a File node into PointObj or RefPointObj on a volumeNoise node seems to have no effect on the mapping. I've spent a good while looking but I can't find any other way of using the baked UVWs to drive the texture. Any clues?

Thanks.