ADOBE AFTER EFFECTS: Forum Expressions Tutorials Creative Cloud

Warp Stabiliser kills straight RGB alpha output ?!

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Daniel CrooksWarp Stabiliser kills straight RGB alpha output ?!
by on Oct 27, 2013 at 7:01:25 am

I've just uncovered something very annoying. I have a precomp with transparent elements but when that precomp has the warp stabiliser applied in another comp the ability to use Straight RGB is removed and I can only render with pre-multiplied alpha. when i view teh Straight RGB channels I get a black (and super aliased) mask. Extremely frustrating ! Am I missing something or is this just how it is ?


Return to posts index

Roland R. KahlenbergRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Oct 27, 2013 at 9:56:48 pm

It's best to use the Warp Stabilizer at the very start of your workflow. Then ensure that you render out the comp before proceeding with the rest of your workflow.

HTH
RoRK

Intensive mocha & AE Training in Singapore and Other Dangerous Locations

Imagineer Systems (mocha) Certified Instructor
& Adobe After Effects CS6 ACE/ACI


Return to posts index

Daniel CrooksRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Oct 28, 2013 at 12:30:51 am

normally I would, but in this particular case I can't.

and given the normal RGB + Alpha works fine, it does seem odd that WARP disables the Straight RGB...


Return to posts index


Roland R. KahlenbergRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Oct 28, 2013 at 2:42:35 am

Straight RGB always produces harsh edges AFAICR. I just tried Warp Stabilzier FX (renamed accordingly in AE CC) and the inherent Alpha Channel stayed consistent with expectations - good quality.

HTH
RoRK

Intensive mocha & AE Training in Singapore and Other Dangerous Locations

Imagineer Systems (mocha) Certified Instructor
& Adobe After Effects CS6 ACE/ACI


Return to posts index

Daniel CrooksRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Oct 28, 2013 at 3:42:32 am

hi Roland and thanks for looking into this.

I'm probably not explaining myself very clearly. when I say Straight RGB I'm meaning outputting a file that contains the alpha channel and clean (non pre-mutliplied) RGB channels. I use the "show rgb channels" button in the comp window - view as "RGB Straight".

The Warp FVX will output a perfect pre-multiplied alpha but this is no good as I need to the keep the clean (or Straight) RGB info in the file.

for testing create a precomp with a piece of footage in it. Bring that into another comp and apply Warp VFX. now go back to the precomp and apply a mask to the footage. Come back to warp comp and view channels as "Straight RGB", then turn off the Warp effect and you'll see what i mean...


Return to posts index

Roland R. KahlenbergRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Oct 28, 2013 at 8:17:43 am

[Daniel Crooks] "for testing create a precomp with a piece of footage in it. Bring that into another comp and apply Warp VFX. now go back to the precomp and apply a mask to the footage. Come back to warp comp and view channels as "Straight RGB", then turn off the Warp effect and you'll see what i mean..."

Hi Daniel, apologies for not being able to understand/appreciate your issue but my immediate thoughts are that you should commit to the masking prior to applying WS VFX. Your workflow requires the mask to be applied prior to nesting+WS VFX.

I see no rationale, in fact it's wrong to WS in a higher level comp and then to go back down to the precomp to apply a mask/matte as either one of these affects the pixels that will be used by the WS algorithm. However, I don't see how such an unwanted workflow will disaffect an inherent Alpha Channel.

Further, I can't see any issue with what you've described, albeit briefly, it all seems like what one would expect with a Straight Alpha. I am also curious as to why you would require WS with footage that contains an Alpha Channel - this is exactly the step where I thought you could re-work your workflow, ie, apply WS followed by some CG to create the Alpha Channel.

Perhaps it's best that you post a few embedded JPGs - an AEP would be exceptional. I'm also thinking that the issue is not with WS itself but with being able to output a Straight Alpha from AE - for output to an online suite. If so, I've passed this ages ago and the solution is beyond my existing memory's capacity. Again, an AEP and/or screen caps will be good.

Cheers
RoRK

Intensive mocha & AE Training in Singapore and Other Dangerous Locations

Imagineer Systems (mocha) Certified Instructor
& Adobe After Effects CS6 ACE/ACI


Return to posts index


Daniel CrooksRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Oct 28, 2013 at 10:09:40 am

hey Roland

I hear what your saying about doing the Warp first but in this particular instance I can't.

I've put a small .aep here to illustrate.

6687_warpalpha.aep.zip

and here's a jpeg, the top row is with the warp effect disabled, and teh bottom row is warp on. Both of the RGBs and the Alphas look identical but see how the far top right still has all the original RGB info where as the bottom right just has black boxes... ugly...



../dc


Return to posts index

Daniel CrooksRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Oct 28, 2013 at 12:13:16 pm

ah man, it does it with the Pixel Motion Blur effect as well.... I give up.


Return to posts index

Dave LaRondeRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Oct 28, 2013 at 5:12:54 pm

Hey, don't give up, you just aren't approaching it the right way.

You see that Cyan box in your illustration? The one that needs stabilization? Don't even even think about putting that footage into your final comp, the one with the transparency in two places.

Before you do anything, stabilize that footage! Prerender it! Once that's done, THEN do your other AE voodoo. Problem solved.

When you tink about this as TWO AE projects -- one for stabilization, one for creating effects -- your life gets a lot easier.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA


Return to posts index


Roland R. KahlenbergRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Oct 28, 2013 at 6:58:08 pm

Dan, see if the info here -> http://www.jaredisham.com/adobe-cs6-part-3-warp-stabilizer/ helps.

Cheers
RoRK

Intensive mocha & AE Training in Singapore and Other Dangerous Locations

Imagineer Systems (mocha) Certified Instructor
& Adobe After Effects CS6 ACE/ACI


Return to posts index

Pierre JasminRe: Warp Stabiliser kills straight RGB alpha output ?!
by on Nov 3, 2013 at 2:55:21 am

It's an old time bug in AE, if you perform an analysis you end up using the a different code path than the actual rendering of the effect, where effects before including masks are not applied. For our tools that do things like that, we check if there is an effect applied before us and put up a pop up telling that to user (and the only solution is precompose), but makes me think we should also look if someone has masks applied to warn user.

Pierre
revisionfx.com



Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]