Linear workflow one more time

[3D Betrieb]

Hello dear vray forum.
I hope you wont get bored about my lwf-questions, but Im still confused about this lwf stuff.
The first time I had a proper workflow with reinhard color mapping at 0.3-0.5 and I was very sufficient about the image quality.
Now I have to achieve best results so that my maps have to look so close as possible in photoshop as in the rendering. With my reinhard settings my renderings were always washed out, the textures tended to grey.
At this point i decided to use the lwf.

At first I used the following settings:
Customize Preferences:
Enable Gamma/LUT Correction checked
Gamma 2.2
Affect Color Selectors checked
Affect Material Editor checked
Input Gamma 2.2
Output Gamma 2.2 (because I want to save in 8 bit images, cause of our workflow)
The Color Mapping is at linear multiply with dark, bright and gamma set to 1.0
Linear workflow box is UNchecked

Now the colors are very sufficenting, my woodmap isnt grey anymore, but my images tend to burn out.
I cant reach the same "lightquality" as in the reinhard settings

The second way I tried was the Linear Workflow Checkbox in the Color mapping.
My Software Reseller recommended me to use the Color Mapping Checkbox, but the results were even burned out.
In addition the vray help means: "...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...."

Reading in this forum I was surprised to read that bernhard rieder uses an exponential workflow with gamma 1.6. (Rieder Workflow RWF)
Now I got very confused.
Doesnt need the proper linear workflow a linear color mapping?
What are "the right" settings?
How do you avoid burned out regions?
Is there a standard way of using the lwf?

Confused greetings,
Stefan

[tammo]

Your going backwards in time,
stay with the reinhard color mapping.

Besides "Rieder Workflow RWF" was really just a joke,
like if you find that you get good AA results by using adaptiveDMC on 1/6
and call that the "stefan workflow"

There is no way to get a light setup that works in every scene
but using Reinhard color mapping will deal with most problems like burnouts.

If you want to adjust gamma i would also do that in the vray rollout and not in the 3ds max settings.

[rivoli]

well, you're not doing any lwf that way. I guess that's why you're having images with massive contrast between dark and bright areas.
the fact is that lwf has been explained hundreds of times on these forums, and what amazes me is that something as simple as gamma correction can get so complicated when the majority of said explanation are so wrong and confusing. it all started as a very simple thing and ended up, loads of threads later, as something that looks more like black magic.
sticking to the linear workflow button in colour mapping should work, don't know why it doesn't for you. but anyway, I know I would add to the confusion if I started to explain one more time what lfw is and how it works, so I suggest you to read through this very informative post by Intuition were things seem to be summed up very clearly:

http://www.chaosgroup.com/forums/vbu...r-dummies%29#2

[3D Betrieb]

hello tammo,
thank you for your answer.
The RWF I realized as a joke and I know about the possibility of a faboulos swf (stefan workflow)
Zhe problem is that the reinhard colormapping isnt a good choice for me anymore because all maps get washed out.
I would love it to sty with reinhard...
stefan

[3D Betrieb]

hello rivoli,
thank ypou for help.
That the reinhard multiplier isnt a proper lwf I understood.
But when I use the settings from your posted aversis tut Im not sufficient with my results.
(Customize Preferences:
Enable Gamma/LUT Correction checked
Gamma 2.2
Affect Color Selectors checked
Affect Material Editor checked
Input Gamma 2.2
Output Gamma 2.2 (because I want to save in 8 bit images, cause of our workflow)
The Color Mapping is at linear multiply with dark, bright and gamma set to 1.0
Linear workflow box is UNchecked)
My textures are very close to the photoshop maps, but the lighted areas get very bright and tend to bun out, I get very strong contrasts and my walls in interieur are at a midtone grey and wont get as white and clean like I wish.
Thank you,
Stefan

[rivoli]

but those are not exactly the settings as described in the aversis tutorial. the tutorial goes through different ways to deal with gamma corrected images, if you follow it along with Ituition's post you should get a fairly good idea of what lfw is meant to be. I guess understanding why you check a box it's way more helpful than having someone telling you what to do.

[3D Betrieb]

Hi rivoli,
yes I think I have a good idea what lwf is and why I need it.
What I made different from the aversis tut is that I dont want to specify the bitmap gamma for each texture separatly so I decided to turn the Input Gamma to 2.2.
Now I can turn the Output Gamma to 2.2 too to burn the 2.2 Gamma in my output images or to tell vray to applie the 2.2 Gamma while the rendering (what is I think the better way).
I thought I understood the lwf thing almost but where am I missing?
Thank you,
Stefan

[rivoli]

actually you don't tell vray to apply the gamma correction by setting the bitmaps output to 2,2. that doesn't affect the renderer, only the way max will import bitmaps. if you want to apply the gamma correction, than you specify it in vray's colour mapping.
in that way you tell vray two things, one is you want it to adapt the sampling to your linear workflow. the other one is, in case you don't tick "don't affect colours", to apply the correction directly to your output (in this way if you save to a linear format you'll get double corrected output).
in case you do tick "don't affect colours", you can preview the result using the srgb switch in the vray frame buffer. if you are all right saving gamma corrected ldr images, then you don't need the srgb button (you will still see them double corrected in the max fb though), and can save them as they are.
I don't know if this is what you're after, because I don't know what inconsistencies you are having between bitmaps and rendered bitmaps, and don't know exactly how you're trying to manage them. in any case that is not a linear work flow as it is often intended, the point of working linearly being for a lot of people stay linear from the beginning to the end, hdr outputs and comping included.

[3D Betrieb]

Hi rivoli.
Thank you for your patience
The workflow is already fine and with the 2.2 in the colormapping a proper workflow I think.
The maps are looking fine!
But my problem is not the lwf itself.
My problem is the burning out of white walls in interieur renderings lit by vray sun and sky.
The reinhard solved this problem very simple for me.
But now my images tend to burn out with white walls.
When I reduce the shutterspeed I get grey walls and a dark room.
What could be a good solution for this problem?
Should I avoid VraySun+Sky with lwf?
Sincerly Stefan

[DanielBrew]

My problem is the burning out of white walls in interieur renderings lit by vray sun and sky.

You need to use the Vray camera with exposure with the VRay sun. You also need to use materials with realistic values for diffuse colour. Out of interest, what is the RGB value for your white paint?

[rivoli]

one thing you may want to try is to make your white material less.. white. one thing which is often overlooked, is that to achieve good contrast, avoid washed out renders, and likely avoid over bright spots, materials and textures must be adjusted accordingly. once you adjust them to appear as you would expect in a gamma corrected rendering, you also have to re-expose or re-light your scene, which take a bit of work. and it may not be the solution you're looking for.
here's a great tutorial by Lele which I found really helpful, you may want to have a look at it:

http://www.chaosgroup.com/forums/vbu...t-Bonus-Script!

[3D Betrieb]

Hi DanielBrew,
hi rivoli.
Certainly I use vraySun + Sky with the VrayCam VrayMats...
I use a nearly pure white diffuse color like 253 in the diffuse color slot.
Maybe your right and a darker value could help me out of problems.
But if i understand you wright rivoli you want to tell me, that good contrast fine textures and a clean rendering needs tweeking a lot.
So I will stay tweeking
Thanks a lot.
Stefan

[DanielBrew]

I use a nearly pure white diffuse color like 253 in the diffuse color slot.

That's very high, I never use values higher than 200 even for white paint. I also limit the values in bitmaps by changing the RGB level to 0.8 in output. It will probably take a bit of getting used to but you should find it a lot easier to to avoid overblown highlights.

[3D Betrieb]

Hi Daniel,
thank you for that advice.
Its very interesting to have a look to the workflow of other people.
I will try it!
Thank you.
Stefan

[DanielBrew]

I hope it helps. There was another thread about materials http://www.chaosgroup.com/forums/vbu...ious-materials you might find it useful.