Going gamma-linear is going better – with Vue
- October 3rd, 2009
- Posted in News
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If you didn’t know – I am definitely a zealot for the newschool rendering techniques, with photometric lights, HDR renderings, and, maybe most significantly, gamma-linear workflow. So when I was looking at some otherwise great Vue renderings, it was always bugging me that they look like silly old CG instead the real beauties they could be. So to spread the evangelism, I fired up Vue 7.5 XStream PLE, and tried some gamma juggling out.
The scene uses the thick cloud atmosphere from the physical presets, global illumination lighting. I have two objects and two materials from the scene – one is a sphere with a simple bitmap texture on it, and the other is the ground with the gray rock preset material.
And finally, here’s the tests:
Default VUE output:
Output with gamma set to 1.8:
Output gamma 1.8 AND materials’ color gamma 1.8:
The images should be pretty self explanatory. The default output looks quite old-school CG. The shadows, light falloff and shadow-midtone contrasts look unrealistic. Boosting the output gamma to 1.8 helps in bringing out the realistic GI look, but also washes out the color maps. At the end, putting a gamma 1.8 on the textures too, remedies the problem, so we have a more realistic render. Have in mind that even if you want to go for a different look, like the filmic low-gamma one I love, this is the better startpoint for post-processing. Take the torch, experiment and preach! Amen and enjoy your new renderings 😉
And how can you apply the gamma correction to the Atmosphere Editor when using VueXStream 8 and 3dsmax ?
Haven’t tried 8 yet, but I guess it has a gamma node you can put at the end of the mat chain too. Or you can render a mask for the sky and gamma that in post.
Or render the whole thing float EXR and gamma that in post. Disadvantage is, you’re not gonna see the real picture before the end 🙂
well… it’s right you can add a gamma node to the texture maps.. and yes you also can add a gamma node to the procedural colors….
but this works just for that…
the major issue is, that you can’t add a gamma correction to the atmosphere. And this is a major problem.
Because the atmosphere is basically the environment which is used to illuminate the whole scene.. technically speaking it’s used for the GI.
That means, you can gamma correct the texture maps you use for your materials, but the environment still lights the scene in a wrong gamma space.
I also realized, that I can’t change the gamma space for materials that are used for trees and plants at the ECO System.
it looks like I am not alone…. read this interesting thread here:
http://forums.cgsociety.org/showthread.php?f=162&t=842551
if you have any answer to that issue, please let us know.
EXR:
even if you would render in .exr you need to get sure you work in teh right gamma space… and it doens’t make sense to work in a linear work flow inside max or maya and after that apply a gamma correction to the sky etc.
so you mean you would like to work in a non linear gamma space all the time, and after apply the gamma correction…
would make sense… but I would say it’s a step backward int a wrong direction.. and it’s also a pain if you can’t see your final render as it should appear in the right gamma space….
it’s really hard getting vue xstream integrated because of the all this major issues… a linear work flow is known in the industry since years.. and I hope I just couldn’t find the right answer yet, and there is a possibility to integrate XStream with a linear work flow.