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Vedrica
11-03-2009, 12:01 AM
How to render a character animation without background in pass, but to make the characther to pick up FG from background objects? Is the right way to turn off primary visibility from all the background objects in layer override?

Edit: i am trying to found an easier way to do this because with this i need to have double the objects of background, one for FG, and one for the interlocking.. Help please!

Nawbean
11-04-2009, 07:18 PM
I dont know if it helps you or not. Yeah the rendering of animated characters with background objects primary visibility turned off, seems to be right way. The only thing is I use COLOR MATTE pass to mask out inter locked object , so that you don't need to use double objects in the scene but you will get separate render layer. If your are not familiar with this work-flow it may be another hectic job for you to create another render pass but once you output color matte pass you will have more flexible control on color correction and composition in compositing software . Color matte pass: Just like alpha pass, rendering different objects with different pure flat color:- red, green, blue, cyan, magenta, yellow, white and black. YOU can use this pass for channel mask during composition.
I hope I am clear.

kuschel33
11-04-2009, 07:26 PM
I would try to subset the character. You get the FG, it renders faster than PV off and you get an alpha channel...

Vedrica
11-04-2009, 09:29 PM
I would try to subset the character. You get the FG, it renders faster than PV off and you get an alpha channel...

I had problem with new render system. It would help iff you tell me how not to render whole composition before rendering defined pass.
What is PV?

Vedrica
11-04-2009, 09:31 PM
I dont know if it helps you or not. Yeah the rendering of animated characters with background objects primary visibility turned off, seems to be right way. The only thing is I use COLOR MATTE pass to mask out inter locked object , so that you don't need to use double objects in the scene but you will get separate render layer. If your are not familiar with this work-flow it may be another hectic job for you to create another render pass but once you output color matte pass you will have more flexible control on color correction and composition in compositing software . Color matte pass: Just like alpha pass, rendering different objects with different pure flat color:- red, green, blue, cyan, magenta, yellow, white and black. YOU can use this pass for channel mask during composition.
I hope I am clear.

Can i just make color matte pass with surface shaders? Is this procedure is compatible with After Effects also (i am not using Fusion).

TaKIKO
11-05-2009, 12:08 AM
I always wondered about this method but never tried it. Try rendering Final Gather only, then save the FG map. Set the rebuild to freeze and hide everything but your character.

Nawbean
11-05-2009, 05:54 PM
Well Vedran, I also use AE for composition and it works well for me. Yeah surface shader is handy for this process but you may need other when you need raytrace the transparencey. And in AE to mask out the certain channel you need to use 3 channel matts and then its just the number game between rgb. You can matte out 9 different objects, including alpha in a pass.
But yes I agree with Markus Seiler that rendering with objects with PV off for getting fg still cost calculation time.

Vedrica
11-11-2009, 04:13 PM
I got it. I will try with subset character set. I only don't know how to bypass rendering the whole image before rendering subset character...

kuschel33
11-11-2009, 08:40 PM
Just set all your character to "primary visibility off". With this you get the whole background.
Tomorrow I will upload my subset script, with which you can easily choose, what geometry to subset...

Vedrica
11-12-2009, 03:39 PM
Just set all your character to "primary visibility off". With this you get the whole background.
Tomorrow I will upload my subset script, with which you can easily choose, what geometry to subset...

The script would be usefull certainly!

You missunderstand my last question. When i batch render with Maya 2009 new passes feature, Maya first render whole image, and after that it renders just what i want in pass. With this i have two images after rendering (whole image which i don't want, and pass image which i want). How to bypass rendering whole image? That way the rendering is long.

Htogrom
11-13-2009, 10:01 AM
It might be the bug with 2009 batch rendering. It just takes 2-10 times than ordinary viewport render. I used the script to render from maya.

JasonA
11-13-2009, 08:24 PM
I don't believe this is possible. Using the AOV pass system requires masterbeauty to be run regardless of what other pass you want out. if you want just the pass by itself, you'll have to run in on a render layer instead.

....When i batch render with Maya 2009 new passes feature, Maya first render whole image, and after that it renders just what i want in pass. With this i have two images after rendering (whole image which i don't want, and pass image which i want). How to bypass rendering whole image? That way the rendering is long.

Htogrom
11-13-2009, 11:30 PM
Workflow I tried and it worked was:

1. Bake final gather to one map via freeze.
2. Render background without character.
3. Then to all background objects set primary visibility off, set final gather receive off.
4. In render globals put the final gather map you used earlier for background and put it as secondary fg map, leave primary empty. Set rebuild mode to ON (Only primary map is rebuild).
5. Render character. It will pick up final gather from surrounding environment.
6. Render one alpha pass, background black, char white, to get intersections.
7. Render shadow pass from character to background.
8. Render one pass with occlusion shader, where character casts occlusion and background receive. You can do that with mip_matteshadow shader.
9. It is important to have passes for both character and background because shadow pass must be merged.

This workflow is little bit tedious but it works.

It is really shame that you can't control which shader uses which fg map. I would like to see someone here with mr shader writing skills to make shader that will have fg_map file entry. That would be ubercool. I know it is possible in renderman, I don't see reason why wouldn't be possible with mr.

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