Velocity Pass Issue

[annabanks]

Hi everyone,

 

I'm having trouble utilizing the velocity pass the Vray outputs in AE.

In the Attribute Editor, I typed in the highest Max Velocity value I could find using single-frame renders (I also tried just typing in the resolution width, going by a tip I found on another forum). I'm rendering openEXR files.

 

Here's the problem:

 

1) The image I see in the VFB under Velocity does not look like the one I see in AE when selecting Velocity in the Extractor plugin.

 

Here's what it looks like in Maya:

Here's what it looks like in AE:

 

2) The motion blur I get when using RSMB Pro Vectors to point at the velocity pass looks awful. There's a kind of uniform blur in the entire image, that affects perfectly still elements as well.

 

Here's what it looks like with RSMB applied:

 

I actually tried rendering out a completely separate HDR version of just the velocity pass, to at least get the output files looking the same as in the VFB, but that still didn't create good motion blur.

 

Does anyone have an idea how to fix this?

Thanks a lot for any help!

[Darius Jablonskis]

Same here. I'm just using 3ds max vray and RSMB and getting the same results as you. Whatever I do i'm getting same results. I will post here if i find something useful.

[Nicolai Bongard]

I have rather limited experience with this but tried to google a bit, and allthough this tutorial is for c4d it apparently goes through "How to set up a multi-layer EXR output for After Effects", so perhaps you can adapt the procedure to your own setup. Hope it is helpful: https://greyscalegorilla.com/tutorials/your-depth-pass-is-wrong/

[Darius Jablonskis]

I have rather limited experience with this but tried to google a bit, and allthough this tutorial is for c4d it apparently goes through "How to set up a multi-layer EXR output for After Effects", so perhaps you can adapt the procedure to your own setup. Hope it is helpful: https://greyscalegorilla.com/tutorials/your-depth-pass-is-wrong/

 

Tried that with no luck.

[Darius Jablonskis]

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

Edited March 29, 2017 by dariusjablonskis
Pictures aren't showing, added url tag instead