LWF Again

[zeronove]

i tried your method, and with sRGB enabled, the results are quite the same in terms of colour/contrast....
what is the advantage of using this method when doing re-compositing of render elements ?? (or what problem can i meet when i'm not using it?) what do you mean when you say it WONT give correct results ?

It strictly depends on which level of accuracy are you looking for

I often bake gamma when I know from the begining that image is almost totally done straight from frame buffer; it's faster
When I know that I'm going to make an amount of compositing, color correction or whatever post producion work, I always save WITHOUT baking gamma and apply an inverse gamma 2.2 curve layer in photoshop (top of the stack).

Trying to summarize the reasons I can say that it's related with the following:
linear space: rgb 128 + rgb 128 = middle gray + middle gray = full black
non linear space: the previous equation is not totally correct

Probably it's not a totally correct explanation but more or less it is

[rmejia]

ok for the max DISPLAY gamma settings, which acts only on max frame buffer.
but the max input gamma setting affect the textures,with both vfb or max frame buffer. right ?
that is why it is un necessary to check lwf checkbox, because that would correct the textures twice if i understoode correctly.

Sorry I might have mentioned that the Max gamma settings affect the display gamma in the VRay frame buffer, they don't. They only affect the bitmap gamma in the VRay frame buffer. The input gamma settings for bitmap files only affect bitmaps in the VRay Frame buffer, here are some screenshots of this in action:

The sRGB button is the one that switches on and off the Gamma 2.2 in the VRay frame buffer. Although sRGB is not exactly 2.2 gamma, but it's pretty close.

[MikeeMax]

that's what i had understood.

Thanks rmejia. u're really helpfull.

[sv]

i tried your method, and with sRGB enabled, the results are quite the same in terms of colour/contrast....
what is the advantage of using this method when doing re-compositing of render elements ?? (or what problem can i meet when i'm not using it?) what do you mean when you say it WONT give correct results ?

so, the idea is you just apply the colour transformation in the viewer only, and you keep all the data as linear, floating point. Vray calculates everything in floating point.
if your doing things like multiplying elements together in a post compositing program, you have to work with linear data, otherwise the resulting recompositing of elements, WONT be correct - i.e. won't be the same as the Beauty RGB image in the VrayFrameBuffer. If you keep the data linear, you can do the correct math in post, otherwise your trying to put back together elements of an image that have the incorrect values (colours) which of course won't work.

FYI - the images posted above - the second image I don't think is correct... the input gamma of 2.2 removes the sRGB profile from the jpg texture. you then re-apply this by viewing the image in sRGB space....

[MikeeMax]

Thanks sv, i wasn't aware of those compositing stuff.
i'll try to multiply some render elements to see what you're talking about.

this thread has been life saver for me. Thanks all.