Wednesday, November 6, 2013

Week 7 - (Light Rig Base Part 2)

Last experiment was a bust

Not only did I panic and use a pre-set mode that worked but I was unable to customise it to my likeliness. The key here is that it worked.

This week my goal was again to achieve a default lighting system for a 3D animation. This time I would be breaking the network of physical sun and sky down (rather than wing it). I had a hunch that if I could understand the parts of how the mode was built, I could customise it to my likings.  

Physical Sun and Sky (PSS)

The ideal lighting situation I was aiming for was an average sunny day in a park at about noon. 

Rather that delve into the web and look into how (PSS) is built, I started by starting with a directional light a moving on from there. The directional light seemed somewhat ordeal due to experiments  I had done in week 4. Bah, Enough tangenting.

In PSS the Directional light has suppressed custom shaders. In both Light Shader and Photon Emitter Physical Sun has been placed. By adding custom shaders both the intensity and shadows features become locked and arent able to be manipulated through the light anymore (my problem with the last experiment). 

Within the Physical sun is the only place to manipulate the shadows and that's just how soft they are.
Physical Sun has further connections with physical sky, connecting most features for them to work well together.

The time of day gets controlled by having the directional light (or its world attributes) connection through the sun slot. This allows the environment to change from a midday setting to a golden evening. 

In order to see what is on screen effectively custom shaders are connected to the camera. This being Physical Sky in the environment shader to view the blue sky and Exposure in the Lens shader.
Finally to help support the distribution of a one light scene final gathering is turned on.

Altogether this builds the product of PSS that is a usable system that can make an environment look good as well as its time of day. For me though it wasn't good enough.     
What I did

After building this from scratch I started to rip out stuff that I felt was hindering me. 

- First to go was the Physical Sky. Having that in the connected to anything is what was responsible for the bluish tint I hated. Stripping it out of the camera shaders did that. 

- There was also no need to have Sun Direction as I was sticking with midday so that was stripped out. 

- I wanted to be able to manipulate shadow opacity and light intensity so the Physical Sun was taken out  (as well as Sky then). 

- Turning off the final gathering brought back thick black shadows. Adding 2 Fill lights for the side and front lit them up. Adding a yellow ambient light goldened up the scene to simulate sun light affecting the environment.

 - Adding a light for the distant background only added depth to the scene to simulate light hitting distance.

- A final light was added strictly for the skybox to the light up a sky. Mainly because the Directional light could not work properly within a dome. 



Final thoughts

The results produced default lighting I was comfortable with. From here there still needs to be creative lighting added in order to really help this scene come alive. I just glad this is all starting to work now.

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