OTOY Forums

Hi,
I´ve been using Octane for years but I have struggled with shadows always. I have adjusted them in Photosop but now I would like to hear some tips to make this easier and directly in raw render.

I attached a typical situation:
Evening light is nice but the shadow over left house is too strong. I would not like to increase Exposure or make sun light stronger because the light wall will get "burned". And if I adjust gamma, it will make the picture look bad. How should I do to make light/shadow a bit more even?

Any tips?

Hi,

Builtdown wrote:I´ve been using Octane for years but I have struggled with shadows always. I have adjusted them in Photosop but now I would like to hear some tips to make this easier and directly in raw render.

3 elements: lighting, shading and "color management" ("image formation").

Builtdown wrote: Evening light is nice but the shadow over left house is too strong.

Unless the Diffuse Ray Depth (in the render kernel) is set too low, then it seems to be expected. High contrast would be caused for various reasons, such as:
- weak light sources (sun included!)
- no scene light bounce (they often do when buildings are close to each other)
- too absorbing materials (albeit it's usually the opposite)
Resources: Octane Kernel Settings

Builtdown wrote: I would not like to increase Exposure or make sun light stronger because the light wall will get "burned".

Too late, already the case. Looking closely at the running male's white shirt for instance, or the kid on the right side. The Octane sun is probably set at its default value (rather low).
Resources:
Octane Lighting
OCIO & DRT

Builtdown wrote: And if I adjust gamma, it will make the picture look bad. How should I do to make light/shadow a bit more even?

What's commonly known as "Gamma" should never be changed. It's usually set to 1.0 "linear" or ~2.2 (sRGB EOTF) but does not suffice to produce an appropriate digital imagery.
Resources: Offline Rendering Digital Imaging 101 (“Survival Kit”)

All the links I have shared may be overwhelming but it is in fact a 5min task for roughly everything, and simpler than it looks (at least in practical).

I would strongly suggest to ditch Photoshop and any Adobe software as none of them are designed for high dynamic range CGI offline rendering post production. Fusion Standalone or Nuke are the top tier recommendations (although not "perfect"), and if the paywall is an issue, I could suggest some free solutions for basic CG post-production.

Feel free to share any question you may have and you are welcome to message me if needed.

Thank you so much. I will go through these and test to make this picture better. I´ll be back.

I made a new test. It went pretty well. I got more light on shadowed areas just as I wanted (under roof and balcony wall). See attachment.

I played with Sun Turbinity and Power, Diffuse Depth and Exposure.

Indeed, glad you've found your way.

No OCIO though. Perhaps overwhelmed? I insist, if you need assistance, I will gladly help.

Builtdown wrote:
I played with Sun Turbinity and Power, Diffuse Depth and Exposure.

Looks much better. Exposure is the key. Also default Octane Sun/Sky power are too low. In reality Sun has more energy and light distribution is much greater because of this. In renderer exposure and highlight compensation should be used to compensate overexposured areas or by using OCIO, Lut's.

If you look on real camera photos you can see that sky is most of the time overexposured if camera "looks" on the building in its view center for example.