I think I got it.
Developpers of RSMB recommend to put the max at 2048 and unclamp the velocity. You don't need to worry about any "max velocity in last frame" anymore, the floating point information, the 2048 and unclamp is taking care of that, so much room for pixel information with 32bit...
Im also saving render as vrimg, with EXR/VRST/VRSM 32-bit box checked.
After renderin vrimg I'm getting wrong looking velocity pass. Mines looks like this
https://ibb.co/i8BZfa
To fix that i'm using vrimg2 tool to extract my velocity pass from vrimg file. Then i'm getting correct looking velocity pass. At first maybe it looks like there is just solid color, but don't worry there is still all velocity information.
https://ibb.co/mjkMRF
in AE, you need to be setup in 32bit sRGB and linear.
once you drop your velocity pass in your comp, just add a level, and the spikes should be really tight in the center of the level, if it's the case, then your have done everything right. Delete the level
https://ibb.co/j39n0a
add a rsmb pro vector to your srgb img, route it to the velocity pass and put the max displace to 2048 in rsmb as well.
then i'm getting somewhat correct motion blur, need to play with blur amount value to get better results.
Strongest effect can be noticed on two lemons coming from the left.
Render 3dsmax with no motion blur
https://ibb.co/fNRmRF
Render 3dsmax with camera motion blur
https://ibb.co/g0di6F
Render AE rsmb with motion vectors
https://ibb.co/dCtuDv
