vray caustics not creating vrpmap per frame for animation, just keeps overwriting old

[alteredgene]

Hi everyone.

i am attempting to do a caustics animation for work (deadline looming just around the corner) after hours of tweaks, finally got the caustics to look the way i want.

i thought caustics GI map would be same as irradince map (prepass mode) or lightcache (single frame) that when i render animation, it will save caustics map per frame, where i can load it up later.

eg.
caustics_001.vrpmap
caustics_002.vrpmap
...

however, i found that even after rendering the whole animation, caustic map will just keep overwriting itself, basically i just get one

caustics.vrpmap, sitting on my drive..

tried looking up google, and the forum but seems nobody else had the same problem.

is it just me?

thanks in advance for any help!

added -----------------

after further experimenting, found out photonmaps behave similar fashion (as in through out the whole animation it will not save photonmap per frame, will just overwrite the old map.
are there any way of producing caustics map per frame in animation? so i can load up the map and tweak the settings to my liking?

thank you in advance for any help!