What scene is able to compare VRay and Maxwell ?

[flipside]

I agree Gijs, I just talked about comparing with a real picture, because you said 'right' balance, which is indeed very subjective and can differ a lot for various purposes.

The intensity color mapped image indeed looks nice, and will probably look balanced very well for most people (especially clients who usually hate burn outs)

[Gijs]

The nice thing about intensity exponential is that keeps the saturation up to a certain level, whereas exponential washes out all colors and HSV keeps the saturation even in the hottests spots in the image.

[Morbid Angel]

Interesting tests...I've noticed that by lifting the gamma to 2.2 the whole image brightens, not respectivly to shadows. Unlike in maxwell, where the darkest areas are preserved.

[Gijs]

I've noticed that by lifting the gamma to 2.2 the whole image brightens, not respectivly to shadows. Unlike in maxwell, where the darkest areas are preserved.

I am interested to see some pictures to understand better what you mean with this.

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Additionally, this is a picture with a red flooring. On top the rendering with the gamma corrected version below.
As you can see the color bleeding is acceptable and IMO quite natural.

[flipside]

Impressive Gijs, I definatly need that linear space workflow tutorial

[Gijs]

I'm working on it It just needs a bit more investigation and tests like these.

[Morbid Angel]

Gijs, what are your gamma settings in vray? - looks good.

[Gijs]

In fact the only setting that is important is the input gamma setting. If your monitor is calibrated for a gamma of 2.2 and a texture looks good on it, this means the input gamma for this texture has to be set to 2.2. I've set it globally in the gamma settings of Max, but of course you can set it locally per texture as well.
Setting the display gamma correction also to 2.2 helps to get a better material preview.
Then I use the gamma curve in Vray VFB as proposed by Rob Nederhorst to preview what it looks like. If I load the 'dark' image into Photoshop and assign it a profile with linear gamma, it looks as if you applied gamma correction.

What I found most interesting is that even if you are using intensity exponential color mapping, the gamma correction 'rule' still applies. I don't have experience with compositing programs, but I can image that those programs have their own tone mapping algorithms to display a larger dynamic range. But in my case (and probably for a lot of other people that render directly to output) combining gamma correction with exponential color mapping is a good option

[Morbid Angel]

do you set texture gamma in photoshop before going in max or in max right off?

[Gijs]

If it is an existing texture, I think it is better to set it in max, otherwise you need to save another copy. If however you can obtain textures that are already in linear space, it is better to keep them linear. The problem is that when going from linear to gamma 2.2, the dark tones loose the most information, because the dark regions are streched the most. This is visible when working with 8 bit textures. If however you have 16 bit textures you can make a safer switch from linear to gamma corrected (in other words, less chance for visible artifacts)

(Additionaly to emphasize the importance of bitdepth:
If you render to floating point RGB then there is no risk to go from linear to gamma corrected. If you save the linear image as a 8bit image and do the gamma correct in post, you get banding for sure)

[Morbid Angel]

i see...what i ment was, where exectly do you adjust gamma in the texture in max? (since we got so many options)...all this time i was working with vray's color mapping. Totally forgot about vfb gamma thing.

[Gijs]

My max gamma settings are as following:

-enable gamma correction: ON
-display gamma : 2.2
-Bitmap files:
+ input gamma : 2.2
+ output gamma : 1.0

btw: all vray settings are default (no GI saturation or contrast adjustment or materials with increased GI multipliers or any other tricks)

[jacksc02]

im looking forward to the tut gijs!!

[Morbid Angel]

hmmm.....when i did the settings as you suggested, my scene went even darker then what i had...

[Gijs]

I hope I did not confuse you, but those are only the max gamma settings. If you render with Vray framebuffer, you need to apply gamma correction for viewing as well, because it doesn't use the max gamma setting. If however you copy your 'dark' Vray framebuffer to a max frambuffer it will have the gamma correction applied.