3 ms·
The blue light of the sky is technically the result of Rayleigh scattering of the sun through the atmosphere, which can be emulated (and often is these days! [0
by Jasper_ 5y ago
The blue light of the sky is technically the result of Rayleigh scattering of the sun through the atmosphere, which can be emulated (and often is these days! [0]), but fair; it's often cheaper and easier for an artist to model them separately. I was going for a classic physics demonstration to point out how simple sources can often result in beauty.
[0] The classic is Naty Hoffman's 2002 work on atmospheric scattering http://developer.amd.com/wordpress/media/2012/10/GDC_02_HoffmanPreetham.pdf http://developer.amd.com/wordpress/media/2012/10/GDC_02_Hoff... , but it has been developed over the years, e.g. Sebastian Hillaire's work on both Frostbite https://media.contentapi.ea.com/content/dam/eacom/frostbite/files/s2016_pbs_frostbite_sky_clouds.pdf https://media.contentapi.ea.com/content/dam/eacom/frostbite/... and Unreal Engine https://blog.selfshadow.com/publications/s2020-shading-course/hillaire/s2020_pbs_hillaire_slides.pdf https://blog.selfshadow.com/publications/s2020-shading-cours...
- nine_k 5y agoWhile technically true, this is not how most 3D animation software models light — even if it (roughly) models Rayleigh scattering in solids, like opal or ground glass. In all realistic rendering software, skylight and sun (or other celestial bodies, like Moon) are modeled as separate sources of light, with different light characteristics.