Lighting issues in a stadium

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Liverpudlian82
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Tue May 05, 2020 9:06 am

Hello,

I am currently doing another stadium and would appreciate some hints and ideas on how to tackle a few issues I have with the lighting

Image

Image

The issues I see are these:
  • Contrast between the light on the pitch and on the stands is too heavy
  • Concrete in the shades has a blueish reflection also the material is gray
  • They goal nettings appear too thin/too dark and are not visible enough. The goal netting is made out of real geometry and not a texture and has the correct physical size
What I've tried so far:
  • Playing with iso/shutter/gamma correction etc. results shown in the pics are the best I got after hours of tweaking
  • Activating ambient occlusion and varying its intensity. It does make the darker parts appear brighter, for example under the roof, but all in all the picture looks less photorealistic and more like from a computer game
  • Adjusted the power of the sun with more or less the same effects I got from tweaking the exposure settings
  • Adjusted the soft-shadow-multiplier value of the sun. It helps a lot with balancing the contrast, but as the shadows get softer, the picture looks more and more like a shot made in the evening of an autumn day and not an afternoon shot in August (which I am after)
  • Additional Image-based-lighting from a white background image, about the same effects as activating ambient occlusion
  • Inserting a fake emitter plane covering the entire roof-opening sending light downwards, still the same as activating ambient occlusion
Software used: Thea 2.2 for SU plus Photoshop for the lens flare effect (but nothing else)

Any other ideas on how to get a more balanced lighting?
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mrwip
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Tue May 05, 2020 9:59 am

Hi Liverpudlian82,

Interesting subject !

Could you share your current display and rendering settings (a screenshot for example), it will help showing you a good direction.
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mrwip
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Tue May 05, 2020 10:01 am

For the netting, I've often encounter this kind of issues, and the most efficient solution is to use a texture and cheat on the size of the net (x2 / x4). It's not ground truth but it will look like what you want.
Liverpudlian82
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Tue May 05, 2020 3:43 pm

mrwip wrote:
Tue May 05, 2020 9:59 am
Hi Liverpudlian82,

Interesting subject !

Could you share your current display and rendering settings (a screenshot for example), it will help showing you a good direction.
Image

Thx!
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mrwip
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Tue May 05, 2020 4:09 pm

Ok, but you haven't send here the "rendering" tab, it's the one with the small gear symbol, it's the most important in this case.

In any case, you could try with (in presto MC) a tracing depth of 6, with no diffuse depth or ambient occlusion.
In the sky settings, set the turbidity to 4.5 instead of 2.5, it will be less blueish.
Liverpudlian82
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Tue May 05, 2020 5:45 pm

mrwip wrote:
Tue May 05, 2020 4:09 pm
Ok, but you haven't send here the "rendering" tab, it's the one with the small gear symbol, it's the most important in this case.

In any case, you could try with (in presto MC) a tracing depth of 6, with no diffuse depth or ambient occlusion.
In the sky settings, set the turbidity to 4.5 instead of 2.5, it will be less blueish.
Sorry :/

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nigec
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Tue May 05, 2020 6:01 pm

wow... you don't need diffuse depth that high... I don't even check that box with 2.2 unless I wan't to limit the amount
Tracing depth is really high too, render times are probably a lot higher than they need to be, unless you have a bucket load of glossy glass or a mirror maze you'd never need much more than 15 tracing depth (in my opinion)
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Liverpudlian82
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Tue May 05, 2020 6:10 pm

Render times are not an issue as I have fairly high-end hardware.

So what are tracing depth, diffuse depth and extanded tracing actually doing? I thought the higher the values the better the image quality as more light bounces are calculated?!
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Tue May 05, 2020 6:27 pm

there's a good example of tracing depth here:
https://www.thearender.com/forum/viewto ... th#p186181
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Tue May 05, 2020 10:30 pm

Liverpudlian82 wrote:
Tue May 05, 2020 6:10 pm
Render times are not an issue as I have fairly high-end hardware.

So what are tracing depth, diffuse depth and extanded tracing actually doing? I thought the higher the values the better the image quality as more light bounces are calculated?!

Honestly, trust my experience on this, there are a lot of settings in Thea, but hardly 10% of them are needed to do a nice looking render, in almost every situation.

Look at the following image, in orange you'll find, on my opinion, the only settings that are really necessary. I do all my renders with that, and it works great. The only things that you have to adjust really are :

- The size and aspect ratio of your image.
- The iso and Highlights / shadows to control how much light there is.
- Vignetting, contrast and white balance to control the color and final aspect of the image.
- Denoiser, if needed.
- Set tracing depth to 8 and check that extended tracing is on (it normally is by default). Do not add any tracing depth or AO.

THEA SETTINGS.jpg


Leave all the rest on default, press render, and enjoy !
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