LWF button debug list

[ARTECONI-CGI]

Hi all,

I'd like to create a list of problems you have encountered using the LWF button from the VRAY color mapping.

Since the LWF came out I have tried all the possible settings combinations to solve that problem and so far I have found that the LWF button on the color mapping is the best option for me although the same software house discourage its use.

I am sure that there are other users who adopts this workflow and I'd like to compile with them a list of issues that they've met using it.
Spot3d declares that this options is only used to convert old scenes done in gamma 1 to the new LWF but doesn't explain exactly what is wrong with it.
As well, after V-RAY for Maya came out, I see more and more people using this magic button.
The same software house doesn't clarify it's position about the LWF suggesting a preferred method, the only things that I have noticed is that all the video tutorial offered by Chaosgroup are using a gamma 1 setup.

Most of the people agrees that loading their textures with a color correct node .4545 and setting up 2.2 on the color mapping panel is the way to go nowadays.
(and using the don't affect color + srgb button on the VFB if you don't want to bake it)
I do seriously find that this setup doesn't really work for me. fresnel, 2sided material, fogcolor and fastsss2 doesn't look great to me with this setup.

I mainly work on interior scenes and in my personal case I find that although it creates very nice and bright images it just doesn't look photorealistic. It just doesn't.

Anyway getting back to the main topic: LWF button on the color mapping panel.

I find this as the best implementation of the LWF so far.
I still get nice contrast and I don't have to color correct any single texture that is really annoying to me.

So here are the 2 things I have found that I think are wrong at the moment. I'll be happy if you can add your experience.

FastSSS2 material: the ssscolor map and the scatter color map looks washed out. They still needs a color correct node to load the texture at .45
Vraylightmaterial: it looks washed out. Still needs to be color corrected with .45

What else?

Kind Regards,

Giacomo.

[wsp]

I also use the LWF button workflow but I havent noticed any other issues except the ones you already explained.
Would be interesting to know if someone else noticed some more issues.

[Svetlozar Draganov]

The most proper way to set us LWF with Vray at the moment is the old and very well known method:
Max Gamma 2.2 , reverse-gamma color-correct node for each texture and color - and Vray Gamma 2.2 if you are working with VFB.

Linear Workflow button gives very fast results - because you don't need to color correct everything , but it as you know it doesn't apply inverse gamma on every texture or color slot.
Also if you are mixing a few bitmaps with Composite Texture for example - Vray apply the inverse gamma correction at the end result not on every single image before the actual mixing.
These are the reasons why we do not recommend it, which doesn't mean that you can't use it, but we just want to warn you that there are a few things which doesn't work right with it.

As a conclusion - if you want truly LWF use the old method where you add manually gamma correction to every texture and color - if you want to speed up the process at the cost of not so accurate LWF use the magic button.

We are working on this topic and there will be improvements in the future Vray releases.

[voltron7]

good to hear this IMO, thanks!

[wsp]

I often work with large scenes with hundreds of objects and materials. I simply just cant afford the time to gamma correct everything manually.
The LWF button might not be 100% correct but frankly it makes my day so much easier and I'm happy with the results i get with it so I dont really care. I dont do any fancy compositing, mostly beauty/background/velocity/zdepth/fog.
Almost always I use reinhard color mapping and adjust the burn value to my needs. So I burn the gamma in my renderings.
So for me it is much less effort to manually correct the things that isnt corrected with lwf button than the other way around ("the old and well known method".)
I wish chaosgroup could expand the functionality of the the lwf button to support more but until then we can fill in this list so that we all know what currently ins'nt supported


The list so far:

1. FastSSS2 material: the ssscolor map and the scatter color map looks washed out. They still needs a color correct node to load the texture at .45
2.Vraylightmaterial: it looks washed out. Still needs to be color corrected with .45
3.if you are mixing a few bitmaps with Composite Texture for example - Vray apply the inverse gamma correction at the end result not on every single image before the actual mixing.

So does anyone got something else to add to the list?

[ARTECONI-CGI]

Hi wsp,

Thanks for partecipating to the list.
Referring to the composite map I wonder what is the turnaround? Just apply a 2.2 gamma on top of the shader and counteracting then every single map / color? That is far too complex to do...

I can't confirm it now but in past I had the feeling that something in the vrayfog still needs correction....

[wsp]

I found a couple of more things to add to the list while searching the forum.

The list so far:

1. FastSSS2 material: the ssscolor map and the scatter color map looks washed out. They still needs a color correct node to load the texture at .45
2.Vraylightmaterial: it looks washed out. Still needs to be color corrected with .45
3.if you are mixing a few bitmaps with Composite Texture for example - Vray apply the inverse gamma correction at the end result not on every single image before the actual mixing.
4.Just keep in mind that this options doesn't apply revers gamma curve to the maps assigned to the environment slots
5.this options doesn't apply revers gamma curve to the maps assigned as a texture for the lights

Keep adding stuff if you wish...

[ARTECONI-CGI]

Thx wsp,

yes I confirm about the texture not corrected on the vraylight....

[snivlem]

LWF button looks like its going to be depreciated in Maya - is this the case for you Max users?

[wsp]

I don't know but i really hope not. That would make me depressed, if they don't come up with something else that works even better of course. I really dont like the other workflow where you have to manually correct everything.