April 04, 2012, 11:15:16 pm
As maybe a workaround, bit of guessing as not time to try:
For simple situations and static objects, would it be possible to add in the same but duplicated(re-imported) object at same position, but not make transparent, rescale down slightly so that above water is hidden by main glass object, below water is seen as not transparent and as the refraction would normally alter the look of size etc then scaling would not be noticeable. Make the material a single color.
Alternative, make an object from the original glass object in DCC and cut it for the shape for only the below water, import and position as needed.