Time Remapping changes Motion Blur

[jotoenne]

Okay, here is my problem.

I have a comp with some footage. I did a 3D camera track, created a camera and tracked some elements into the shot. I activated motionblur on those elements to get them to integrate into the footage nicely. Works fine (the camera footage obviously has some "real" motionblur). I precompose everything and then i want to do some time remapping for the whole thing (speed it up). But now the motionblur on my tracked in elements is way too much and it doesn't fit in anymore (the camera motionblur in the footage obviously does not change, because it is not a moving element in after effects).

Basically i just want time remapping to change the speed but leave the motionblur in the precomp as it is. Any way to get it to do that? I could not find any solution.

Best regards

Jo

[Rick Gerard]

Turn off Collapse transformations. That should solve your problem. If it does not, open Composition Settings/Advanced and reduce the shutter angle. If the speed is twice as fast, change the shutter angle from 180º to 90º.  If that does not work, turn off motion blur in the nested comp (your pre-comp), and add Pixel Motion Blur to the time remapped layer. 

[jotoenne]

Okay, found a sort of solution.

With Collapse Transformation off it uses MB Shutter Angle Settings from the precomp. But with a lot of speeding up, this becomes way to blurry.

With Collapse Transformation on it uses MB Shutter Angle Settings from the main comp, but with a normal angle of 180° or 90° it is of course still way to blurry (with very fast time remapping)

So my hacky solution now is to set the angle to a very low angle setting (like 10° or something), either in the precomp (collapse off) or in the main comp (collapse on), does not matter. With fast time remapping this now becomes usable.

Pixel Motion Blur is not an option because it would blur the camera footage too, and i do not want that. Plus it does not really work good with a speed up this fast.