linear work flow .... again

V-Ray V-Ray for 3ds Max General
1

Ok having discovered the wonders of linear workflow after dishing it for so long. I now find a big flaw in the entire scenario:

greyscale maps have a 2.2 gamma pre-applied to them.

this doesnt seem like much but:
it doesn’t make sense to apply a 2.2 gamma to a bump map, a specular map and an opacity map …

does it?
so I did some testing and found that diffuse maps need the 2.2 and greyscale maps need 1.0

OR am I wrong? eh ? Please somebody tell me

If I’m right: is there an elegant way of achieving this?

Raj

2

I think you are right…bump, displacement, normalmaps need gamma 1 so far i know

3

ay there’s the rub:

if you change the input gamma to 2.2 this is applied to ALL bitmaps, and I believe it is also the case with the LWF button

so its a case of setting the input gamma to 2.2 and then changing each non-diffuse map to gamma 1 manually

OR leaving the input gamma to 1.0 and changing each diffuse map to 2.2 manually.

either way its a lot more work than I like - but a man’s work is never done especially as there are bonus virgins on offer(see thread on Vray2.0).

Raj

4

it’s faster if you keep 2.2 and when you load the map select gamma 1 only because you would have more maps with 2.2 than 1…or in protoshop change the gamma for those maps with the inverse 1/2.2 and in max set 2.2 for all the maps

5

If i have an organic model, I usually have a bump, reflection, refraction and possibly opacity map. Thats 1:4 ratio of maps. 4x the work. But I will investigate.

but wait - someone said to throw out LWF all together. OH NO… sacre bleu..Use reinhard he says.

Raj

6

So long as it looks good and gets the job done with minimal work, who cares what you use.

edit: we actually got an animation from a company a while back which was rendered in linear as full float - the images were so contrasted and mostly completley white - they’d done the tonemapping in post.
It’s a very strange way to do it, but they still got amazing results from it.

7

If you mean the “Linear workflow” option in the V-Ray Color mapping settings, then this is not quite so. The selected gamma will not be applied to bump and displacement maps, only to color maps (diffuse, reflection, refraction) in VRayMtl.

Best regards,
Vlado

8

@vlado

to quote (I am forum GUI impaired so I will use cut and paste)

“The selected gamma will not be applied to bump and displacement maps, only to color maps (diffuse, reflection, refraction) in VRayMtl.”

how does this button affect the FastSSS2 material where you plonk the traditional texture map in the SSS color slot?

raj

9

Can anyone point me to the most up to date linear workflow tutorial ?

I tried in the past to use LWF but didn’t like it, I want to try again… 8)

Thanks.

10

It’s pretty straight forward but constricting if you use one particular method (1.0 gamma in vray, sRGB in VFB). What didn’t you like about it?

11

The very handiest way to do it now is to change your gamma in color mapping and turn on linear workflow - stick to only vray materials and that’s about it.

12

So…

Color Mapping: Gamma Correction: Gamma: 1.0
Linear Workflow: Checked
Vray Frame Buffer: sRGB: on

That’s it?

No need to color correct textures or Change MAX Gamma Preferences (enable LUT correction, Bitmap Gamma: 2,2) ?

thanks
Bill.

13

colour mapping to linear
bright and dark at 1
gamma at 2.2 (you have to tick dont affect colours adaptation only)
tick linear workflow button
vfb and srgb button

change max gamma preference to 2.2?
Only enable LUT correction only if you want to use the max frame buffer

thats it

Output to exr. it makes life easier

14

What I don’t understand/like about this workflow is that you can’t use color-mapping. Most of the time I don’t want to do all that in post - I want to see and work with my render with color mapping applied. Is there any reason why this isn’t the case when using the adaptation-only option?

15

Noone is saying you can’t. Color mapping is basically a post processing filter. It’s the same as if you were to take the picture into photoshop and alter it there. The “linear workflow” part is about what happens internally in Max with the textures and colors. UNLESS you want to use linear workflow in Photoshop/Nuke/Ae as well… Then you can’t use color mapping in Max, but you can do those things in your post program anyway.