Hi,

to animate footprint in the sand, I would do boolean difference between the ground (a terrain maybe) and a model of  foot print.

I don't know if it is possible in poser to export just the feet in order to use them for the boolean operation. Maybe it would be better to use something else than exactely the foot because it have to be irregular a little. Like a terrain. Hope it helps.

Anty

PS : I've done a little scene to see if it works, but I can't upload it on this forum :-( ask me if you want it: :-)