Linear workflow, Vray, and Maya

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  08 August 2011
Originally Posted by cpt_O: Either way, what I find strange is that most tutorials (and many users) that discuss Vray for Maya rendering, enable the LW option and just move on without further fuss...
If you do this, you really are taking a "head in the sand" approach. Better you learn how to implement a proper workflow (which, by the way, is not simply leaving the box unchecked, just as much as it is not simply checking it).

Originally Posted by PerfectLine: The trick is getting it to show up @ mmb color picker colorbox.
Yah, thats the trick I cant seem to figure out. I'm still trying from time to time, but if you can give us a clue it would be most appreciated.

  08 August 2011
Ah, its not clicking right on the color box. its MMB on the text next to the colorbox (left of). Essentially a variation on the RMB menu that is activated but by the MMB instead.

The color picker is tricky, its not just dividing by .4545 because a fully saturated color still gives you the fully saturated color result even in numeric value. Somewhere as the color desaturates and also the value comes down from 1.0 there is a calculation being made.
AKA KC / Intuition
  08 August 2011
Originally Posted by PerfectLine: MMB on the text next to the colorbox
Thanks for the hint. Thats something I had not tried yet.

  09 September 2011
VRAY and Multiply node?

Hello guys, any help on this will be very helpfull

Seems like vray and multiply node dont like each other

  09 September 2011
multiply works in vray 2 for maya.
  09 September 2011
Can u see the image? Yeh, multiply node seems to work, but what's wrong in my aproach? In mental ray this works perfect. Not sure what's the problem with vray :S
  12 December 2011
I'm having problems with the settings you posted on the first page David;

I have the LWF box unchecked, File texture nodes that have the 'texture input gamma' applied are fine, however any Vray material that I've used the swatch to pick a colour for the diffuse slot comes out really overblown.

Any idea what's happening?

Last edited by Richard7666 : 12 December 2011 at 02:04 PM.
  12 December 2011
Originally Posted by Richard7666: I'm having problems with the settings you posted on the first page David;

I have the LWF box unchecked, File texture nodes that have the 'texture input gamma' applied are fine, however any Vray material that I've used the swatch to pick a colour for the diffuse slot comes out really overblown.

Any idea what's happening?

This is were you would apply a gamma correct node with .4545 applied to the Gamma value, and then choose your appropriate color via the color value swatch. I think this is up for debate, but it has been confirmed on the chaosgroup forum as well. Hope that helps,

  09 September 2012
I understand that the docs claim Linear workflow checkbox is a quick fix - but would love to hear how is not a proper solution. It seems to gamma the whole shader (maybe too much as it would also do specs etc) - but otherwise all I can think of is that if using one uses linear textures such as exr format - it will also correct these and can cause issues.I am yet to test this but regardless I believe chaosgroup should explain what that checkbox actually does - why its not a proper solution so I can make a more educated decision about my workflow.

Secondly this whole process is imho still a mess because gamma 2.2 and sRGB are not the same. To some this may be negligible but it can make quite a difference in the deep dark values.

If i'm applying a sRGB LUT to my renderview to check my work - I need sRGB correction for textures AND my swatches. That not currently possible unless im missing something.

Is it to much to ask for true WYSIWYG workflow. *Sigh*
"Yeap, im certain - I spent 50hrs making sure it was a cow"
  09 September 2012
It's kind of a mess isn't it.

From what I understand on all the Max V-Ray linear workflows, its simply a matter of this. One setting which affects everything correctly including swatches.:

Why this can't be brought to Maya after the fact, I simply cannot comprehend it, or more probably rather, I fail to underestimate the challenge in adding this to Maya???? Not sure.
  09 September 2012
Yeah max has got it right. Annoys me every time I see it.

Vray intergration in maya is a bit messy to - Extra attributes rather and a vRay AE template menu addition. Vray shaders mixed in with maya shaders rather than getting there own tab. Names look more like proc names than actual names...
Oh well.
"Yeap, im certain - I spent 50hrs making sure it was a cow"
  09 September 2012
I think Vray in maya is integrated pretty well a lot better than MR ... now of course it can be improved but LWF is better and easier doing in Vray than MR I believe ... I agree that vray could have his own tab ...
LDEA Kon Kuatica
  09 September 2012
This is the 3th day on the internet trying figure out the correct workflow on V-RAY.

I am having strange contrast issues(I did not get this thread till today).
ChaosGroup Thread -

And here are my tests (I started out testing ply to vrmesh converter and landed on LWF):-

1st image:-


a little more Hi-Rez -

4th:- (this was just to get clarity on "affect swatches" check box).

NOTE: I haven't added a .454 gamma node to my swatch in any of my renders, nor have I selected "convert images to sRGB for rednerView," instead I am using Maya's RenderView's color management and kept the "image color profile as Linear" & "Display Color Profile as sRGB" !! I am not facing any prob, in fact I get 99% as Vray's frame buffer when you turn the sRGB switch on. Here are the test images with settings -

1 point i kept emphasizing on threads here and in ChaosGroup was that..
In Gnomon's recent tutorial, by R.Nederhorst on Archetype, he keeps the LINEAR WORKFLOW button checked on, not saying that his methods are the final verdict but he seems to render with no problem, though he uses a tiled .exr format for this textures and uses gamma node with values he feels gives GOOD contrast and uses the color balance as well.

Also in this particular tutorial he uses LWF switch turned on

Was also wondering why SePu used CLAMP OUTPUT in his settings on this thread


I made a mistake, R.Nederhorst on Archetype does not use LINEAR WORKFLOW button, got confused with his V-Ray Primer documented in which he has turned on LINEAR WORKFLOW button

Last edited by govindk : 09 September 2012 at 04:01 PM.
  09 September 2012
Forgive me for contradicting about MR, I might be naive...nonetheless here's my thought after reading through this thread.

In Mental Ray -
(1) You change the setting under color management,
(2) and under texture file node (depending on what you have set as input under color management),
(3) render window for viewing properly
(4) add .454 gamma node to swatches...!!
(5) rendering in 16 bit or 32 bit exr or similar linear supported format...DONE!! (hope I didn't miss anything)

In V-Ray-
(1) Turning on all the buttons under color mapping and setting Gamma to 2.2
(2) Adding a texture and selecting the bit map input gamma under Vray extra node for 8-bit files
(3)sRGB button for V-Ray Frame Buffer
(4) Adding .454 gamma node to swatches
(5)rendering in 16 bit or 32 bit exr or similar linear supported format

How is it easier than Mental Ray, when we are following "almost the same procedures" to make things work properly in LW.Flow?

We still add .454 gamma in vary just like mental ray, we still need to specify it to V-Ray about 8-bit images..!!
I might have made the point completely wrong, it's been just 3 weeks I am using VRay, but its something that occurred to me while reading through. So apologies if I wrote something stupid as like all, even I am a bit confused regarding this after reading and watching different methods on the web. And will Appreciate it if some clears this WORKFLOW issue.

Last edited by govindk : 09 September 2012 at 10:48 AM.
  09 September 2012
Frustrating isnt it. All we need is Chaosgroup to officially clarify how their software works. I intend on writing them on Monday but till then - I've been thinking about it some more.

That Linear workflow button ... My original thought was that all the shader results would be gamma'd - and it certainly appears to do that. If using a mixture of 8bit and 16+bit textures I thought it might cause problems. But then I found this...

and to quote:
Quote: The mystical 'linear workflow' button on whose meaning everybody (even Vray manual itself O !) just glisses or throws in some dodgy ban. Well it is there and it does the whole job. Surprisingly it Can tell the sort of map is being processed (color, normal, hdr, bump) and adjust things accordingly.

If that is so that it is smart enough to know what to correct and what not to correct - that let me think some more about why they say don't use it.

I think it's basically this. The linear workflow button, where appropriate will remove perhaps only remove using gamma. This is not the same as us removing sRGB from our image using the added attributes on a file texture node. This means the only "correct" way to remove is NOT to use the linear workflow checkbox - and instead use the added vray attr on file textures.

I unfortunately do not have vray access right now so I can't test this - but regardless when I get a reply from Chaosgroup I will clarify it here.
"Yeap, im certain - I spent 50hrs making sure it was a cow"
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