Page 1 of 1

Automate mask feather based on mask movement

Posted: March 25th, 2009, 12:41 pm
by Redsandro
I was wondering if someone already made something like this.
Rotoscoping motionblurred footage is not the easiest in After Effects. It would be good if there's an expression that takes all the points on a mask, and compares them temporally spatially (the positions to the previous or next frame), generating a value between 0 and 1 where 1 is a lot of difference (and 0 is ofcourse none).

Then you could have a feathered value of say 4 + 20 * theValue.

Re: Automate mask feather based on mask movement

Posted: March 25th, 2009, 5:43 pm
by Paul Tuersley
In my experience, rotoscoping motion blurred footage is very easy in After Effects. Just turn on motion blur for the layer and you're done. Am I missing something?

Re: Automate mask feather based on mask movement

Posted: March 26th, 2009, 4:16 am
by Redsandro
Motion blur only works for moving layers.
I mean feathering (not motion-blurring) the right amount for the motion tracked mask to match the motionblur of the footage (the motion blur that is already there), which would obviously increase when the mask moves more (and not the footage so the motion blur option does nothing).

Re: Automate mask feather based on mask movement

Posted: March 26th, 2009, 5:01 am
by Paul Tuersley
Motion blur works on animated masks regardless of whether the layer is moving.

Re: Automate mask feather based on mask movement

Posted: March 26th, 2009, 5:20 am
by Redsandro
Maybe I should feel stupid now.. CS3?
I'll check it out later..

Re: Automate mask feather based on mask movement

Posted: March 26th, 2009, 7:14 am
by Redsandro
What the hell? This is awesome! This is exactly what I want, but better! (Ofcourse after changing blur samples in composition settings to 8+.)
I sooo didn't know this.
Thanks!

Re: Automate mask feather based on mask movement

Posted: March 26th, 2009, 7:18 am
by Redsandro
Now a lot of other animating masks that were perfect mess up the layer though.
I think I know the answer, but I recently learned I am wrong sometimes. :P But can motion blur be disabled for certain masks only?

Re: Automate mask feather based on mask movement

Posted: March 26th, 2009, 7:34 am
by Paul Tuersley
Yes. Select a mask then choose Layer > Mask > Motion Blur > Same As Layer/ On / Off.

Re: Automate mask feather based on mask movement

Posted: March 26th, 2009, 7:43 am
by Redsandro
OMG, AE is awesome!
Thanks.

Adobe should have put a feature movie on that video DVD that came with though. I like watching movies but the manual is written too explicitly to read 'just for fun'.