Often times when one sees a major aspect of a modern application still languishing
in a 32 bit version ,when the main core app has long been 64 bit ,it is due to licensing.
3DXchange , or some parts thereof, may have been leased from a third party
with restrictions on how the code can be altered & redistributed.
We see the exact same situation with the built-in mimic lipsinc plugin in Daz studio.
This function only exist in the 32 bit version of Daz studio.
( that nearly no one bothers to install these days)
when pressed for a reason, by animators, Daz finally conceded it was a licensing issue
and has since released a separate ,paid 64 bit, "Mimic Live" plugin of their own.
The fact that RL is openly hinting that an outright replacement of 3DX
is under consideration, makes me wonder if they have a simlar licensing problem
preventing a 64 bit recompile.
At any rate ,whatever replaces 3DX had better have ALL of the motion retargeting
options for those of us who only use iclone for motionbuilding&exporting
and have no real need to import props into Iclone.