Using Material ID pass in AE

# 1 16-03-2013 , 06:28 PM

EduSciVis-er
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I've been rendering out a material ID pass with my shots, and I assumed there was a very straightforward way to use each color from them as masks or alpha channels in After Effects, however after some googling, it seems that life isn't so easy, particularly if the colors go beyond straight red green blue, or is there a simple way to key or create mattes from the different colors. I should think this is a common and straightforward problem, otherwise what's the point? (Add in the slight complexity that they may be blurred out of Maya, so a single RGB value won't necessarily work).

-stwert

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# 2 16-03-2013 , 08:10 PM

The thin red line
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Dont know if this link is any good for you Swert............dave

https://www.fxfx.net/2010/02/18/how-t...after-effects/

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# 3 16-03-2013 , 08:41 PM

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I suppose so... although it doesn't give perfect results on blurry id passes. Also, either you have to invert the alpha to get a trackmatte (?) or you have to key out every color but the one you want. But it does the job. I've also just had a bit of success using the Change Color effect and then selecting the view > color correction mask instead of the color corrected layer. That seems to have a bit more flexibility with the tolerance?

-stwert

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# 4 17-03-2013 , 03:15 AM

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One option would be to render out non-blurred images, render out a motion vector pass, and add the blur back in comp.

Imagination is more important than knowledge.

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# 5 17-03-2013 , 02:15 PM

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I'm doing pretty significant dof blur, so I don't see a way to do it properly in post unfortunately. But that's a good idea, I'll try that in the next shot I want motion blur.

-stwert

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# 6 17-03-2013 , 09:31 PM

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If you want DOF you could use a z-depth pass instead of a motion vector.

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# 7 17-03-2013 , 09:37 PM

EduSciVis-er
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Thanks, but I've found AE to give pretty crummy results with anything but subtle DOF with a depth pass. I'll post up the finished shot in a day or so, and I'd be interested to hear if there's a post-production way to give similar DOF results. Maybe Nuke is better? I don't know, I've heard that in render DOF is going to give the best results, despite being expensive.

-stwert

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# 8 17-03-2013 , 11:29 PM

The thin red line
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Stwert I think you need some kind of tutorial on this stuff didgital do one on a ant, to meny button that do stuff we dont know...........dave

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# 9 18-03-2013 , 12:40 AM

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Of course, direct out of render will always give you the best result, but it's a trade off of being able to change the DOF without re-rendering in production.

Imagination is more important than knowledge.

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# 10 18-03-2013 , 12:53 AM

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Yeah, so far with my animation, I've done 3 shots, one with subtle DOF, one with medium, and one with significant. The first was fine in post, the second I did in post, but I wasn't as happy with it. The third I just don't see it working with post-production DOF, but I'm sure there's tips I can learn to improve the quality.