iray night rendering

[SgWRX]

looking at night rendering, i found that i can plugin a gradient ramp in the environment slot of the scene, then set to spherical mapping, set black from 0 to 50 and from 50 to 100 set dark blue colors. then i can tweak the output of the map to get some amount of ambient night illumination.

 

i set the mr exposure control to whatever the ies lights are in my scene, then work on the gradient for the ambient.

 

i don't have any night hdri's at this point, so wanted to figure something out other than use mr physical sky which never did night/evening renders properly without adding a lot of unwanted colors. i do know about the color changes you can do, brightness etc... but still sometimes not what i wanted.

[Francisco Penaloza]

Even tho the new sky system in Max 2017 is a lot better, none of the "physical sky" of any render, give you the 'look' we want. Maybe Maxwell render...but even that, there is not better solution that using HDRI. They are cheap, lot of free resources too, most of them will come with a very strong color cast and not white balanced, but if you open any of these images and color balance in Photoshop or even withing 3D Max shader. you will get better results than a simple gradient.

 

This gradient was very good alternative before the boom of HDRI but the latest give you lot of color variances and light articulation that will help your dusk shot looks more convincing.

[SgWRX]

yep. i was happy to do the gradient but this morning i found an hdri i had where the sun was 3 deg above the horizon, i cloned out the sun and it was a much better result! i found an interesting article written about physically accurate night rendering by a university, can't find yet, will post if i do. they really analyzed it well. good read anyway.

[SgWRX]

ha ha! found it, i googled physically accurate night rendering and it's a PDF by graphics.standford.edu.

 

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&ved=0ahUKEwio4IffnZ_NAhWFix4KHVSDCg0QFghNMAk&url=http%3A%2F%2Fgraphics.stanford.edu%2F~henrik%2Fpapers%2Fnightsky%2Fnightsky.pdf&usg=AFQjCNG6zKlcKnrhB4Lvem9PB4aQ97gkww&sig2=0Pbv9xmppdqPnRkRmI9d4g