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Full of Eyes
Full of Eyes
Inspiring
December 10, 2019
Answered

Rendering only a section of a composition?

  • December 10, 2019
  • 1 reply
  • 2288 views

So, I have a 44 second animation that takes about 17 hours to render (4k with a number of precomps). 

 

I have to make a few changes to the animation, but what I need to alter is just a small section of the screen....it is visible for the majority of the scene, but if I could comehow mask out and render just that section--that'd be great. 

 

So my question is, 1) is there any way to do that and 2) would it really be any faster, or would the computer still have to work to render the entire scene, even if only the masked section is actually showing?

 

Hope that makes sense, let me know if I need to clarify anything here.

 

Thanks!

This topic has been closed for replies.
Correct answer imeilfx

Ok. So first of all - 44 seconds even if it is 4K footage shoudl npot render for 17 hours. Ok. I know it can but I'm guessing that your composition is not so compicated that it should. 
So first think about optimalization of your compositions and workflow:
- most common one is to use much images with much larger resolution that it need 
- rendering from to slow HDD or to to slow HDD - depending on what kind of footage you have
As for your question - masking does not help because AE have to count whole composition to show only masked part so your render wont be faster but what you can do is:
- render those parts that will not change - so backgrounds, particles - anything what will not change 
- render several of precomps/layers/effects that will not change and use those renders in your composition 
- render into image sequences - why? During 17 hours of rendering bunch of things can hapen so it is better to have for exaple 1000 frames good and rest corruptred (power outage, issue with files, issue with computer, codecs etc) and then just rerender last 100 frames and join all of them in AME into one f. eg. mp4 than render for 16 hours and by power outage or any other reason land with corrupted mp4 or mov file that can't be saved/player/used and you have to start from the begining. 

1 reply

imeilfx
imeilfxCorrect answer
Inspiring
December 10, 2019

Ok. So first of all - 44 seconds even if it is 4K footage shoudl npot render for 17 hours. Ok. I know it can but I'm guessing that your composition is not so compicated that it should. 
So first think about optimalization of your compositions and workflow:
- most common one is to use much images with much larger resolution that it need 
- rendering from to slow HDD or to to slow HDD - depending on what kind of footage you have
As for your question - masking does not help because AE have to count whole composition to show only masked part so your render wont be faster but what you can do is:
- render those parts that will not change - so backgrounds, particles - anything what will not change 
- render several of precomps/layers/effects that will not change and use those renders in your composition 
- render into image sequences - why? During 17 hours of rendering bunch of things can hapen so it is better to have for exaple 1000 frames good and rest corruptred (power outage, issue with files, issue with computer, codecs etc) and then just rerender last 100 frames and join all of them in AME into one f. eg. mp4 than render for 16 hours and by power outage or any other reason land with corrupted mp4 or mov file that can't be saved/player/used and you have to start from the begining. 

Full of Eyes
Full of EyesAuthor
Inspiring
December 10, 2019

Ok, that's what I thought might be the case (regarding the masking).

 

All of my assets are drawing from and rendering to a Samsung 960 EVO m.2 SSD....as far as I know. So I don't think the drive is part of the bottleneck (though, there could be an asset here or there being drawn from my HDD...)

 

As to the composition....it's a kind of 3D "cut out" animation sort of thing.....This final scene is, as I said, 4K and has three 4K pre-composed scenes in it, each of which has multiple other pre-comped scenes in them (sort of a telescoping effect) at 70-100 or so layers for each scene. Most of those layers are 3D and are PSD files that are 4,000 x 6,000 with a resolution of 400dpi and many of them have effects (turbulent displace, motion tile, radial fast blur etc.), different transfer modes, and track matted layers. There's also lots of 3D camera movement (in all the pre-comps on screen) and 4 adjustment layers over it all......It's all an organic whole and so trying to render out parts that don't change is difficult as everything is sort of connected to everything else. 

 

It's sort of a strange way to use AE, but it's how I've been doing it for about 10 years now.....this one is just taking way longer than normal b/c of all the pre-comps layering up at the end. Typically a render for a whole animation (4-5min) is 12 hours.

 

Your suggestion about rendering in image sequence (I use TIFF) is very good. I used to render to AVI and would get crashes at the very end and lose the whole thing (0_0).

 

Thanks for taking the time to help me with this!

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