Transparency + Motion Blur: Do you hate that they're connected?

Does anyone else hate that transparency gets motion blurred?

I do a lot of effects where the image cuts on, but if I use a transparency keyframe in Action, the motion blur makes the adjacent frame semi-transparent.

I hate that motion blur is connected to transparency and don’t see any value in this. Am I the only one who cares, or do other people?

  • Transparency should NOT be goverend by Motion Blur
  • Transparency should be governed by Motion Blur

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When this is happening I black out the matte I’m feeding into that action layer when I want it transparent, BUT it’s not elegant, takes away the ability to use the material node trick for multiple surfaces transparencies, and forces me to just to be hopping in and out of the action. I wish flame would just do that for me. But I don’t know enough about how it works to know if the two can really be separated?

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If I’m using transparency as a cut I change its interpolation to constant. No motion blur then…


This is interesting that this is a solve :thinking:
Thank @Sinan

Is motionblur using multiple calculations between frames? So even a one frame animation from 0% to 100% has tweens and if using default curve we see an animated fade up but switch to constant and there is no curve even in the motion blur tweens.

I would imagine “samples” defines the subframe steps, or samples @PlaceYourBetts, though honestly I never considered that constant would solve the problem and it makes perfect sense.

@Sinan FTW.


Damn. Thank you for this. I was ready to write up a feature request. Haha.


Another thing to maybe consider is outputting vectors from Action and applying the motion blur in Batch post comp. It’s hella faster than Action rendering, and surely wouldn’t affect transparency.

That was the word I was looking for :+1:

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I know what shot you’re talking about…

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