Calculating backward velocity?

[Robert1977]

Dear all,

I know that with vray you can calculate the forward velocity. Is there a solution to calculate the backward velocity?
The tool dimension for fusion needs both vectors to do a proper retiming of footage, for example from 25fps to 30fps. I want to use vectors as they are then not have to be precomputed by Fusion and it should be a lot more precise.

Thanks for your help and best regards

Robert

[vlado]

I don't think it's possible at the moment unfortunately, but we can look into adding an option for it, depending on how urgent this is for you.

Best regards,
Vlado

[Robert1977]

Dear Vlado,

from my opinion it would be useful. For motionblur it might not be necessary but for Revision Twixtor Vectors In or Fusion Dimension it would be helpful. It would save calculation power and would be more precise than if the tools create their own vectors on the fly. In the meantime there is maybe a workaround. Thought of reversing the cameras animation, but this is more complicated if one has already a stereoscopic setup.
Retiming CG-footage would be necessary if one wants to prepare the footage to be displayed by 60Hz-Beamers (synched with 30fps) as one example.

Best regards

Robert

[Robert1977]

Ups, I have just seen that the standard Max velocity channel is calculating backward velocity, since no motion is calculated in the first frame. So we have it already, Vray calculates forward velocity.
Hope I am right with this.

Best regards

Robert