Auto Hosek&Wilkie lighting by turbidity Tweet

[SSmolak]

Like in other render engines which use Hosek&Wilkie sky model turbidity parameter is not connected to Sun strenght, shadow softness, overall sky power and ambient strenght/color. I made another script ( after automated Exposure viewtopic.php?f=9&t=80367&p=415184&hilit=exposure#p415184 ) that automate lighting using only turbidity strenght. So you can simulate clear sky <-> cloudy sky using only one parameter in realtime which is very useful in animation.

All parameters were very carefully implemented and they are physically accurate.

Main idea was to make automated transition from clear sky to cloudy ambient lighting without changing other parameters than Turbidity. Fully working script with user interface will be ready within days. Small preview how it works :

[KeeWe]

Any chance we get it build in an upcoming release?

[SSmolak]

In attachment first version.

[SSmolak]

Final version. Added Turbided Sky destination power and Sun position so every important parameters are on the same tab.

[AaronWestwood]

Final version. Added Turbided Sky destination power and Sun position so every important parameters are on the same tab.

AutoTurbidity_v2b.jpg

This is amazing! Been playing with it for an hour just now and this works so much better than what's built in. The automation and realism come out of the box, love love love it.

Following from your other threads, now we just need an auto exposure/auto WB (as options ((not from you, but built in )

[SSmolak]

Glad to hear that you like it

Updated version with White Point temperature correction slider.

Please take in mind that Octane default white point is set to 15% because I think that by default it is little to warm. My default 0% was measured on 75% white wall material and Sun at 45degree to be exactly white without yellowish Sun color cast.

This version needs to select proper Octane Camera Tag ( not Camera Object ) to make color correction works.

[SSmolak]

Final new revised version.

Sky lighting was done from one of the best HDR's from PG Skies

Clear Sky - is 1216_v5.hdr ( https://www.pg-skies.net/products/1216 )
Cloudy Sky is - 1927_v5.hdr ( https://www.pg-skies.net/products/1927 )

Cloudy Sky Parameter at 0% is exactly simulation of clear sky HDR map and Cloudy Sky parameter at 80% is exactly simulation of Cloudy HDR map.

New version has all parameters at 0% by default to make them as real as possible to simulate these HDR lighting.
You can change "Cloudy Sky" percentage and all other parameters will simultaneously ( internally ) change too including sky color cast shading, Sun intensity, Sun shadow fallow and more.