comping in PS render passes (help with belnding modes) :(

[lukx]

I rendered all possible g-buffer passes from vray (saved as tga files) and now I'm trying to put it in ps together but can't come up with something that looks like straight rgb render. What blending modes I should use. I'm using raw gi and raw light with linear dodge and both are over diffuse but it's burned. reflections and refractions are in screen mode. I decided to use passes becasue when renderign pure rgb I'm loosing reflections in windows (yes affect alpha is ticked in glass material).

[jonnybefree]

hi lukx,
maybe this helps,

http://www.chaosgroup.com/forum/phpB...ic.php?t=13818

best regards
jonas

[lukx]

thanks Jonas I saw this topic but it not quite helping me.
Also I don't know what's wrong but I got this white borders around glass. I was trying to use defringe but it's horrible.

[lukx]

I also noticed that when saving tga with premultipled aplha it's different (It's annoying to save 1000 differtent tga types, and what if I close max.I will have to render again to save correct version!!!)

here pics with alhpa premultiplied:

[Morbid Angel]

well, comping in photoshop is not a good idea. White lines you are seeing are the alpha channel premultiplication. Im not sure if such option exists in photoshop, probably in new ones it does, basicly you need to premultiply the alpha with the image.
Also check what have you rendered your pass against. I.e. you must always render pases againsta black, not blue, not white but pure black.
I also suggest comping in after effects or a composite packedge..

[lukx]

I'm rendering always with black background. When saving tga I unchecked pre-multiply alpha so I guess it saved straight alpha. But notice that then alpha looks bad comapred to tga saved with pre-mulipled (my two examples).

[Morbid Angel]

what i mean is alpha channel can be interpreted by a comp software differently. So you can save it any way you want, but in comp packedge it can be read in several different ways.

[RErender]

You might be able to clean it up with the options under layer/matting in PS but like Morbid said, PS is not a compositing software per se.

[Morbid Angel]

indeed, these are called matte chokers. It compreses shirnks or expans the alpha, thus eating into the actual image.

[lukx]

http://www.chaosgroup.com/forum/phpB...ic.php?t=14725