linear workflow and antialiasing/shadow sampling

[chib]

Didn't find a post talking about it, but I guess the search function doesn't work well
I was wondering, if anyone has ever worked in linear space, if that doesn't annoy you that as antialiasing is performed in linear, when you apply a sRGB LUT to your image, it often reveals dirty artefacts on area shadows, and less noticeably on anti-aliased edges (gaps on thin edges, etc...)
So, and that's because this post is in the 'wishlist', I was wondering if it wouldn't be great to add a function to perform adaptive anti-aliasing and other kind of samplings on gamma corrected values, to be able to still work in linear but avoiding all these artefacts...

As I'm not a professionnal about linear workflows, if you have any suggestions or explainations, I'm listening!
thanks,

Paul.

[alias_marks]

You might find this helpful - http://www.aversis.be/tutorials/vray...l_gamma_03.htm

particularly the part on color mapping quality.

[instinct]

This is what the "Dont affect colors" checkbox in the color mapping is for. If you set gamma to 2.2 and check that box you will get a linear image that is sampled correctly.

Kind Regards,
Thorsten

[chib]

hmmm... I quite don't agree with you guys... if you set gamma to 2.2, you don't get a linear image, that seems quite obvious. you get an image that looks like linear but is actually encoded in sRGB...
Just try to save it in vray buffer exr file, and load it in nuke, and you'll get a surprise! a 2.2 gamma corrected image with a 2.2 default LUT in nuke = an ultra bright image
So you have to cheat and tell nuke it's in sRGB?? rather dirty I think...

[alias_marks]

I think this is getting a bit more involved than I can actually explain why the way it is the way it is... however to get around that problem I always have to save out my exr's with a .4545 gamma correction and I'm generally happy with the aliasing result. I'm not sure if it's the right way or whatever, but it's they way I've found to work in conjunction with the www.aversis.be workflow

Also, if the aversis.be workflow is set up right, you should be getting a correct image in the vfb without depressing the sRGB button....

for what it's worth... my 2c

[instinct]

@Chib : This only works if you turn on the "Dont affect colors" checkbox. And then it does what it says: It doesnt affect colors and you get a linearly encoded exr but the sampling is done gamma corrected.

Regards,
Thorsten

[chib]

>alias_marks: this workflow seems ok, but I don't know how to output .45 exr from vray actually...

>Thorsten: I didn't understood the first time, my apologies! that's exactly what I was looking for! many thanks...

hmmm this thread should be deleted now

Again, thanks for the fast answers guys.

Paul.

[phizikl]

i also work linear, what is the linearworkflow chekbox for?

[rmejia]

i also work linear, what is the linearworkflow chekbox for?

From the help:
Linear workflow - when this option is checked V-Ray will automatically apply the inverse of the Gamma correction that you have set in the Gamma field to all VRayMtl materials in your scene. Note that this option is intended to be used only for quickly converting old scenes which are not set up with proper linear workflow in mind. This option is not a replacement for proper linear workflow.

[phizikl]

thx


great avatar btw