Maya 8.5 Sun/Sky Rendering Bad

#101

what did you mean?
i’ve read the whole thread - but your answer is confusing me now.

#102

gamma built in option that you set give you the right thing.

on the second test it looks like you ungamma your texture only what is missing is a lens shader that apply the gamma back.

#103

is that just a lambert sphere, with a constant ‘grey’ color?

#104

yes it is just a standard lambert material.
so which lens shader would you recommend to use?

#105

This is what it all comes down to. Some people need the simplicity and photographic quality of Maxwell Render, while some people need the flexibility and animation power of mental ray. Both do their jobs well. We can want Maxwell to be faster and want mental ray to be easier and that’s fine. It’ll just take time in both cases.

So Smart reply,

I am with you 2, Jovex :wink:

#106

Maxwell is not ideal for the crowd that wishes to get into doing animation.

#107

it seems, here is something wrong.
why did no one betray which lens shader i have to take (maya7.0)? - so many people wrote, they got good results with the gamma node.

btw. i don’t think i’m missing something.
i convert my texture in photoshop to sRGB, save it, load it in maya - make the gamma node in front of the texture with .454 - so it is translatet to gamma 1.0. - well - do i have to translate the whole image back to 2.2?

i would really appreciate someones help.

#108

It’s because you are not reading carefully, people don’t like to repeat. This thread is about Maya 8.5 (see title!), the lens shader/tonemapper is mia_exposure_simple.

#109

i know, but what about maya 7.0
do you mean - all renderings before maya 8.5 are wrong because all textures are to light and burned out?
ok, but my question is already answered, i’ll take the maya built in framebuffering, i get good results in maya 7.

#110

No, you should “ungamma” your input textures only if you are applying gamma to your render output.

#111

:thumbsup: I absolutely agree with my friend Gabba!
Yes MR needs years of studying diagrams a physic laws but for me it’s a great pleasure to render an image like this in half an hour at a 2288 px resolution :stuck_out_tongue:

dedicated to MW user mcyorian

I can’t see any washed out color :rolleyes:

#112

a small setup done testing physical sky in interiors . physical sky , all mia_materials and two area lights .
how can camera exposure can be controlled , for eg . with so much brightness in the room , the sky should almost be white .

scene file and floor texture can be downloaded here :

http://forums.cgsociety.org/showthread.php?f=87&t=459488

#113

Here’s an example with the use of the new mia materials, the sun/daylingt system and the tonemapper. Takes a lot of time to render, but I like the result.
The only problem is to get rid of the blotches on the ceiling and the walls.
I used Maya 8.0 Can some tell me if it is worth using maya 8.5 ? Are the rendertimes shorter ?

#114

If I increase my hdri intensity I will also make all normal surfaces look too bright. Is it possible to increase intensity on reflections only?

#115

how can you ungamma the textures?

#116

I personally hate doing this but sometimes I’m just getting too desperate. Sorry.

#117

Heh. Everybody laugh at mech7 now.

Okay. This has been a mind-crunching, yet strangely fascinating ride.

Here’s where I am so far:

The problem: Rendering with mental ray produces washed out textures.

The reason: Something to do with colour spaces gone bonkers. I’ve done all the reading and understood (some of) it, but non-techies (normal people) really do not need to get into the details. Might even save you your sanity. Really.)

The solution: There are 2 that I can see so far (both work, but I’m not entirely sure if both are absolutely correct. Somebody please correct me if I’m wrong)

#1

  • Connect your file texture to the ‘Value’ of a Gamma Correct node.
  • Set all 3 Gamma values to 0.45
  • MMB drop the Gamma node onto your shader (use default connections)

The texture in the render should now look exactly like the texture you created in Photoshop (or wherever) and not some desaturated ugly mess. Of course, I use the word “exactly” loosely. Please compensate for coloured lights or anything else that might alter the appearance (common sense people…)

Note that you don’t just need to do this for file textures, but for any texture really. For solid colours, set the Value on the Gamma node to the colour you want, dial down to .45 and connect to the Color slot of the shader.

This method can be a bit of a drag when you have something like 50 shaders in your scene. That’s why I use method number 2.

#2

  • Create an mia_exposure_simple node (found under Lenses)
  • MMB drop this onto the camera you intend to render with (use default connections)
  • Set the Gamma on the node to 1.0 (I have a feeling doing this might be frowned upon, but the results it produces are exactly what I’m after. I would love some input from the Higher Ones (you know who you are…) on the repercussions of taking a step like this.)

Cheers!

#118

avinashlobo, the two methods are complimentary, not exclusive. I can’t explain it any better than has already, but I’ll still try explaining: most of what you see on your monitor has a gamma applied to it, typically around 2.2 (it varies). So when you look at photos, textures, color swatches, etc., they all have a gamma of 2.2. Mental Ray, by default, renders without any gamma applied. Light in these renders does not look right. So you should apply gamma (i.e. 2.2) to your render output so that light looks right. The problem is that if you apply a gamma of 2.2 to your render while using input textures that already have a gamma of 2.2, which the vast majority do, you are effectively washing out your textures. So the solution is to “ungamma” your input textures (1/2.2 = gamma 0.454), so that you may then properly gamma your render output. You can ungamma with the gamma node (#1), so that you can then gamma your render output, for example with mia_exposure_simple (#2, but typically with a value of 2.2).

Maybe this pitcure will explain it better… notice how without render gamma the light (sky in this case) is too dark:

#119

Hey, thanks for the explanation. I think I’ve finally understood now. There’s no escaping “un-gamma-ing” your textures because you’ll invariably want to adjust your render output from linear (1.0 gamma) to gamma 2.2.

I still haven’t quite figured out how this all meshes with color space profiles for monitors and individual images themselves, gamma settings on the video card, little gamma profiling apps that run on startup, etc. but at least there’s some light now…

#120

Hi, again. I have another question.
How can I use a 2.2 gamma in my render view during test renders?
If I got it right I should un-gamma my color maps with 0.455 gamma correction node, so that I’m working in a linear way. But then things tend to get dark, so I would want to add a 2.2 gamma to my render view while I’m testing. For the final output I have to render without that gamma and add it later in post. Right?
You’ve already mentioned the mia_exposure_simple lens shader but I can’t find it (is it Maya 8.5 exclusive?). How can I work in a similar fashion in Maya 8.0?
There is another way around this which I’d rather not use. You set the mr framebuffer gamma to 0.455, as this will add 2.2 gamma to the render and 0.455 to all (non-float) images (is this correct?). The problem is that it’s doing it to all (including value driving maps - bump, spec, etc.) images. Then I have to un-gamma all images, except the color ones which isn’t convenient.