Disable Max Gamma Correction and use VRay's LWF button?

[ARTECONI-CGI]

Just to add some more to the list of things I think are not working properly following the workflow suggested by danb4026.
The vraysky and the kelvin colors. Vraysun & sky to my eyes works better with the LWF button, maybe because the colour gets corrected...
Kelvin: try to choose the same kelvin value on a vrayies and on a photometric light. You'll end up with 2 different colors? why? Is this because of RGB vs Floating?

BTW I just want to highlight the fact that I have partecipated to few threads about LWF in the last few months and ironically the same people from Chaosgroup keeps on contradicting themselves on the correct linear workflow.

- Vlado in this thread confirming the workflow posted by danb4026

- Svetlozar Draganov suggest to use the LWF button on this thread http://www.chaosgroup.com/forums/vbu...494#post550494

- The same Svetlozar Draganov suggest a different approach again: http://www.chaosgroup.com/forums/vbu...676#post565676

So, guys, what are we doing here? It looks like you are a little bit confused about it....

I would suggest AGAIN that you publish a proper correct linear workflow on spot3D, so we can save you a lot of headache.

I have the feeling that the right one is the last one, just manually color correct the gamma of the maps and color input.

Again, after 5 years, can we have a magic button that does it for us? We can't color correct every single thing everytime....
The worst thing is that most of the places I freelance for in London uses as standard a workflow that is not correct, and please don't try to tell them they're doing it wrong...


.... just to add some more confusion. Can you confirm that correcting the entire shader is wrong? I have seen few tutorials about Arnold and they seems to color correct everything: maps, shaders and lights... mmm...

Regards,

Giacomo.

[mcnamex]

The funny thing about this thread, is even tho some one is using the wrong approach in the right hand they can produced stunning results...

[ARTECONI-CGI]

Hey mcnamex,

I agree with you 100%.
My conversation is strictly nerdy and technical. In the right hands this software shines.
I just would like to nail the concept properly.
I don't look at myself as a top artist and I'm not trying to blame the LWF if my renders aren't top quality.

Regards,

Giacomo.

[LudvikKoutny]

I found the difference between correct and incorrect usage of LWF to be performance, not quality. So you may still produce stunning results with incorrect approach, it's just going to render a bit longer.

But of course there is difference between using incorrect LWF setup and not using LWF at all.

Anyway, it too confuses me that Chaosgroup staff themselves can not agree on what is correct LWF setup in Vray

[vlado]

Anyway, it too confuses me that Chaosgroup staff themselves can not agree on what is correct LWF setup in Vray

Hehe, I know which setups are correct (there is more than one possible correct set up) and I have explained them multiple times; I have also explained which is the preferred setup. Other people may have their own opinions and that is their right, of course...

Best regards,
Vlado

[ARTECONI-CGI]

Hi Vlado,

Thanks for your post and thanks because you've already explained me once what is your opinion on the LWF.
The fact that doesn't convince me is that you suggest a "preferred" setup.
I think that gamma is a math operation applied to the images/color etc...
There's shouldn't be opinion and point of view about it. It's not subjective. Either it is right or wrong.
All the 3 setups I have mentioned above produces a different render if you start to add reflections etc etc...
This means to me that there's a single working LWF and other 2 that gets close or implement it in a different way.

If the workflow that you suggest is to manually correct maps and colors I keep on thinking that it would be sooooo great if you give us a button that does it for us.
I'm sure it won't take too much to write a script or to correct what's wrong with the LWF button we already have.
I am used to scenes with more than 10 milions polygons and more than 10 people working on it, I am not able to check that everybody has properly colorcorrected the material.

Again, no offence, but assume that I am a new user: why should I go through 30 threads on the forum trying to understand what is the latest opinion instead having it clearly written in the manual of the software.

If there are more than one correct workflow why don't just choose one (the most correct or the easiest) and promote it on your website instead of leaving it for who is ready to read 10 pages of threads. You have to admit that this is a hot topic on the forum and I am sure that Chaosgroup will only benefit from putting it into spot3d.

Kind Regards,

Giacomo.

[LudvikKoutny]

Hehe, I know which setups are correct (there is more than one possible correct set up) and I have explained them multiple times; I have also explained which is the preferred setup. Other people may have their own opinions and that is their right, of course...

Best regards,
Vlado

I actually struggle to find a single correct setup at the moment:

Gamma 2,2 in Color Mapping, Don't affect colors ON and sRGB button in VFB ON = Reinhard color mapping not working

Gamma 1,0 in Color Mapping, Don't affect colors OFF and sRGB button in VFB ON = DMC sampler slow due to the resolving noise on different levels than what is perceived under sRGB display.

Gamma 2,2 in Color Mapping, Don't affect colors OFF and sRGB button in VFB OFF = Images saved with wrong gamma

LWF button = numerous times mentioned it should not be used

So, are there any alternatives that would simply work?

I have searched the forum a bit, and i might have found some setups you have described, but probably not all of them. Wouldn't it be wonderful to have them all from you in a single post? And even better if the post was made sticky Even on Spot3D there is no entry about correct LWF with Vray and Max.

[Neilg]

Gamma 2,2 in Color Mapping, Don't affect colors OFF and sRGB button in VFB OFF = Images saved with wrong gamma

Change the output gamma in max then.

[LudvikKoutny]

Change the output gamma in max then.

Yeah, i think that could work... I just have not seen anyone having output gamma set to 0,454 before... I always thought that correct LWF revolves around keeping image data linear during entire process...

[Neilg]

Change it in photoshop then, if you're rendering to full float then the saved gamma being wrong doesn't change the image. It only matters how vray sees the gamma.

[ARTECONI-CGI]

Again I watched few other's rendering engines implementation of the LWF and they confirm to correct both the textures and colors.

What I can't understand is how the procedural maps, 3d maps and falloffs has to be implemented.

Assuming that we use the LWF from the gamma & lut panel: everything at 2.2 + gamma 2.2 on the color mapping map.
(btw I am pretty sure this is not a correct implementation of the LWF)

For example the fresnel button on the vraymaterial: is it corrected or should it be counteracted?
And eventually how can I do it? Probably I have to disable it, then use a gradient map set to fresnel and on top of that use a colocorrect node set at .4545
Again a gradient map or a noise map: is it fine as it is or should be corrected?

That's seriously screwing my mind, I will really appreciate if someone could help solving the doubt.

[mcnamex]

Apologies but my post was not meant to provoke you for asking, the same thought cross my mind to the inconsistencies with LWF Approach from Chaos.

Hey mcnamex,

I agree with you 100%.
My conversation is strictly nerdy and technical. In the right hands this software shines.
I just would like to nail the concept properly.
I don't look at myself as a top artist and I'm not trying to blame the LWF if my renders aren't top quality.

Regards,

Giacomo.

[pixela]

Where do we change Bitmap Input and Bitmap Output in max 2014?
I can't find the parameters under Gamma&LUT tab. Are they set to 2.2 by default now?

[vlado]

Gamma 2,2 in Color Mapping, Don't affect colors ON and sRGB button in VFB ON = Reinhard color mapping not working

This is the best approach; for the next service pack, the Reinhard mapping works in that scenario.

Best regards,
Vlado

[LudvikKoutny]

Where do we change Bitmap Input and Bitmap Output in max 2014?
I can't find the parameters under Gamma&LUT tab. Are they set to 2.2 by default now?

Max 2014 is (or at least should be) smart enough to identify format and open/save with correct gamma setting

This is the best approach; for the next service pack, the Reinhard mapping works in that scenario.

Best regards,
Vlado

Thanks, that is what i wanted to hear