Composite various levels

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Falam

Composite various levels

Post by Falam » 02 Jun 2013, 04:50

I've run into a bit of problems compositing various diffuse and specular passes/channels. In photoshop I multiple the specular level and specular raw, then I did the same for the diffuse raw and diffuse level, then with the two pairs, I tried all the blend modes possible. The composite doesn't even begin to look like what is fired out of the render ?

Edit: This is how I'm compositing the diffuse layers;

diffuse_level (screen)
diffuse_result (multiply)
diffuse raw (base layer)

If that is correct, why is everything is so dark, the image is more brighter in the render, for diffuse things should lighten up.

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Maximus
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Joined: 09 Jun 2009, 15:45

Re: Composite various levels

Post by Maximus » 05 Jun 2013, 13:03

Sounds a gamma problem to me.
Would be nice to have some info on what you doing:
what are your render settings, what format did you output your render, are you using gamma correction?, are you using photo exposure lens shader?, did you output linear image?, do you have gamma correction option turned on in Softimage preferences? Did you try some other compositing software? Photoshop is quite horrible when it comes to 3d compositing.

also an image speaks more than 100 words, so please show us something.

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Daniel Brassard
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Joined: 18 Mar 2010, 23:38
Location: St. Thomas, Ontario
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Re: Composite various levels

Post by Daniel Brassard » 05 Jun 2013, 14:24

Same conversation on the list:

https://groups.google.com/forum/?fromgr ... mGPEqv8oUs

As said, work in linear workflow,

http://kobayashystips.blogspot.ca/2009/ ... image.html
http://softimage.wiki.softimage.com/ind ... ce_and_HDR
http://vimeo.com/28966508
http://www.3dtotal.com/index_tutorial_d ... a9T_0DvuoM

Try to use a compositing software (FXTree, Composite, Nuke, etc.)

Add gamma at the end of the compositing pipeline, if you have gamma added in your layers, they will add/multiply with each other and you will never get the same result as the beauty pass.

Use OpenEXR files if you can in the compositer. OpenEXR file are HDR file, linear by default.

Watch out for the texture images (jpg, bmp, tiff, pic) that have gamma correction embedded in the format. You may have to correct that in the render tree to remain linear. Image converted to OpenEXR that have gamma embedded will not be linear either (a direct pic conversion to exr file will have gamma added to the linear file, so you will have to correct that). Read the Softimage Wiki for more details.

Good luck!
Last edited by Daniel Brassard on 05 Jun 2013, 20:03, edited 1 time in total.
$ifndef "Softimage"
set "Softimage" "true"
$endif

Falam

Re: Composite various levels

Post by Falam » 05 Jun 2013, 19:56

I'm looking and looking for how to create strictly a FG channel/pass ?

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Daniel Brassard
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Joined: 18 Mar 2010, 23:38
Location: St. Thomas, Ontario
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Re: Composite various levels

Post by Daniel Brassard » 05 Jun 2013, 20:06

$ifndef "Softimage"
set "Softimage" "true"
$endif

Falam

Re: Composite various levels

Post by Falam » 05 Jun 2013, 20:11

Daniel Brassard wrote:http://www.si-community.com/community/v ... f=10&t=706
http://www.youtube.com/watch?v=MTaC6hbdS1Q

A quick search pop those, good luck!

Dan
I knew I was going to be shamed :) x_x

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