Linear Workflow in SP3

[MoonDoggie]

What exactly does the "Linear Workflow" checkbox do in the color mapping settings in sp3?

Do I still need to set my gamma and lut preferences in max? Do I still need to have gamma "2.2" typed in the color mapping settings? Does having that checkbox checked override all of my max settings? vray color mapping settings? I'm confused

[vlado]

From the help index:

"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."

Best regards,
Vlado

[marcdevon]

Will someone post a sticky for the new "official" setup for LWF for VRay 1.5 SP3 for all posterity?

[timmatron]

So if you already have some maps that have been imported as 2.2, then it will be double corrected? I'm still not totally clear on this. But it does affect all the diffuse colors which is kind of nice, so you don't have to do that manually...er, right?

[duke2]

The existing Linear Workflow we all know and love is the preferred option. As Vlado said, this is for older scenes that don't use the LWF setup.

I think, anyway.

[Sascha Selent]

...will automatically apply the inverse of the Gamma correction that you have set in the Gamma field to all VRayMtl materials in your scene...

This option is not a replacement for proper linear workflow.

Hi.

Now I´m confused too. Isn´t this exactly what to do in linear workflow? Applying inverse Gamma manually by ColorCorrect to every material in the scene?

If the LWF-checkbox does the same - what is the difference? Do we have to be careful because it does it for VRayMtl only?

...to be honest: I´m not that familiar yet with LWF - newbie - but as far as I understood it´s this: Apply e.g. gamma 2.2 -> apply gamma 0.4545 to material. Is there more research to do for me?

[RErender]

In a pure workflow bitmaps would be created and saved linearly, I suppose.

[s0real]

Hi.

Now I´m confused too. Isn´t this exactly what to do in linear workflow? Applying inverse Gamma manually by ColorCorrect to every material in the scene?

If the LWF-checkbox does the same - what is the difference? Do we have to be careful because it does it for VRayMtl only?

...to be honest: I´m not that familiar yet with LWF - newbie - but as far as I understood it´s this: Apply e.g. gamma 2.2 -> apply gamma 0.4545 to material. Is there more research to do for me?

so to apply linear workflow to a scene that isn't set up as linear you simply check the linear workflow box in color mapping and set the gamma in color mapping to 2.2?

are there any other steps?
do you need to adjust the gamma in max preferences?

[pg1]

had a very quick play with sp3 yesterday

s0real
"so to apply linear workflow to a scene that isn't set up as linear you simply check the linear workflow box in color mapping and set the gamma in color mapping to 2.2?"

is correct

Do not change the input output bitmap numbers in max preference dialogue leave them at 1.0

Dont forget to tick dont affect colours adaptation only

It gives almost a perfect match to the autogamma script
http://www.chaosgroup.com/forums/vbu...ight=autogamma

I posted a while back except new lwf in vray is faster than autogamma and less memory overhead as it doesnt apply a bunch of colour correct maps like autogamma does

[Robert P]

So if i get it right you can do the following:

1. under "cutsomize>preferences>gamma and LUT" you set:

- gamma 2.2
- do not check affect color selectors
- check affect meterial editor
- input gamma set to 1
- out put gamma set to 2.2 (in this way if you save a jpg you dont have to overide it with 2.2, because th exr's are saved as gamma 1 anyway because of the "dont affect colors")

2. Under color mapping in the vray render engine you set:
- gamma 2.2
- check dont affect colors
- check linear workflow

I did some test and it seems to work fine. In this way you dont have to use any color correct (or lp_autogamma) and your color selector will display the correct colors.

correct me if i am wrong

[MoonDoggie]

I know how to setup LWF, however I don't think you need to check "linear workflow" in the color mapping settings, which was the intent of my original question, trying to find out if I needed it checked or not. Currently all signs point to "no".

[RErender]

If your bitmap textures are saved at 2.2 (normal for windows) then you either need to use color corrects with gamma applied or use the max gamma or the gamma in the bitmap loader or use the option in color mapping to do it for you.

[simmsimaging]

RobertP's list seems correct to me.

I think it's an either/or sort of thing. You can manually set your bitmaps to 2.2 on loading (max dialog), you can set in the input gamma to 2.2 in the gamma preferences (and then all get loaded that way), you can use the colour correct shader and set it there, OR you can use the LWF toggle in the Vray rollout. Using more than one will give you double-corrected images.

Right now I'm using basically the same setup as RobertP wrote, but I use an input of 2.2 set in preferences, and I actually turned off the LWF button. The reason I did that was that the Max image viewer uses the general preference setup so when I occasionally loaded an image to check it in Max (max Frame buffer) it would not match/look correct. A small thing, but annoying.


b

[Robert P]

The good thing about this setup is that you can view your color selectors in a normal way. This gives a much better range in selecting your dark colors (more intuitive). And no necesity to use color correct. Indeed the bad thing is, as i also noticed, that your texture will be overcorrected when you view the material from your material editor. if you want you can correct this by setting the display of max to 1 instead of 2.2. but then you get the problem that when you copy a image as a clone form the vray frame buffer (in to the max frame buffer) that it will look to dark because of the gamma 1.
We have also now chosen to look at the materials in gamma 1 so not only the selectors but also the affect metrial to 1.
For me the color selector is the most important feature.

[fourthand11]

I'm wondering if I've been running improper LWF.

If I run this configuration from here on out is it accurate?

Max 'Gamma and LUT' settings:
-Check 'Enable Gamma/LUT Correction
-Gamma set to 2.2
-Check 'Affect Color Selectors'
-Check 'Affect Material Editor'
-Bitmap Files Input set to 2.2
-Bitmap files Output set to 1.0

Vray 'Color Mapping'
-Type 'Gamma correction'
-Gamma set to 2.2
-Check 'Don't affect colors'
-Check 'Linear workflow'

Material Editor
-Do not override bitmap gamma
-Do not use VRayColor map to gamma correct diffuse colors

If this is correct it just seems easier than adjusting each bitmap and diffuse slot. If I'm wrong than I suck. Ha ha.