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Every so often i revisit the "photorealistic" earth model i created for a job a while ago and try to do a better job on the clouds and atmosphere.
ive tried many times to try and get something volumetric and physically correct working, but always end up returning to my current hacky solution with gradients and falloff maps. i hit dead ends with any of the potential methods available in vray:
vray env fog - doesnt support proper light scattering so doesnt shift colour realistically -- a blue atmosphere should tint towards yellow-red the further the light travels through it as all the blue wavelengths are absorbed/scattered
see here:
https://www.nasa.gov/sites/default/f...059e025207.jpg
vrayscattervolume - might be possible to get reasonably realistic absorbtion and scattering if the right colours were dialed in, no idea what those should really be. , i had some success in getting a colour shift, but not very realistic. however impossible to get the soft fade out into space at the edges.. doesnt support volumentric textures so even a hacky distance tex based fade from earth to space wont work.
vraymtl translucency -same as scattervolume
vrayvolumegrid - as env-fog, doesnt scatter light correctly.
The clouds i guess can live with, i even had some success with a volumetric version but am not yet happy with it... to be honest even the stupidly high res textures i have (75k pixels wide) dont really cut it when you want to get decently close, especially repurposed as displacement maps.
however the atmosphere i have, despite looking ok when illuminated from side or front (even then its missing something) and even at the sun terminator where ive done some hacky stuff with gradients and distance tex to get an approximate reddening at sunset:
it all falls apart when lit in the classic shot of the sun peeping out from behind earth, i.e. lit from behind:
i am also missing all the volumetric goodness of clouds, and the earth itself, casting shadows through the atmosphere like this:
appreciate thats actually cgi, but its still a very nice effect, just a bit more exaggerated than the real thing (and much nicer than mine)
so, my question is, has anybody here (devs included) got a way to simulate a realistic planetary atmosphere in vray? i know its possible, as seen in a bazillion sci-fi films, just not sure if Vray can do it. or if its just me being ham fisted with the tools. (yes im throwing down a gauntlet)
ive tried many times to try and get something volumetric and physically correct working, but always end up returning to my current hacky solution with gradients and falloff maps. i hit dead ends with any of the potential methods available in vray:
vray env fog - doesnt support proper light scattering so doesnt shift colour realistically -- a blue atmosphere should tint towards yellow-red the further the light travels through it as all the blue wavelengths are absorbed/scattered
see here:
https://www.nasa.gov/sites/default/f...059e025207.jpg
vrayscattervolume - might be possible to get reasonably realistic absorbtion and scattering if the right colours were dialed in, no idea what those should really be. , i had some success in getting a colour shift, but not very realistic. however impossible to get the soft fade out into space at the edges.. doesnt support volumentric textures so even a hacky distance tex based fade from earth to space wont work.
vraymtl translucency -same as scattervolume
vrayvolumegrid - as env-fog, doesnt scatter light correctly.
The clouds i guess can live with, i even had some success with a volumetric version but am not yet happy with it... to be honest even the stupidly high res textures i have (75k pixels wide) dont really cut it when you want to get decently close, especially repurposed as displacement maps.
however the atmosphere i have, despite looking ok when illuminated from side or front (even then its missing something) and even at the sun terminator where ive done some hacky stuff with gradients and distance tex to get an approximate reddening at sunset:
it all falls apart when lit in the classic shot of the sun peeping out from behind earth, i.e. lit from behind:
i am also missing all the volumetric goodness of clouds, and the earth itself, casting shadows through the atmosphere like this:
appreciate thats actually cgi, but its still a very nice effect, just a bit more exaggerated than the real thing (and much nicer than mine)
so, my question is, has anybody here (devs included) got a way to simulate a realistic planetary atmosphere in vray? i know its possible, as seen in a bazillion sci-fi films, just not sure if Vray can do it. or if its just me being ham fisted with the tools. (yes im throwing down a gauntlet)
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