Here you go.
Hopefully this works.
SphereTest05_2018.zip (154 KB)
actually probably dont bother! i had a play with volumegrid based option, and a) it doesnt work with IPR so tweaking is painful, and b) rendering is insanely slow, so no good for the animation i have to render.
i think ive managed to get a fudgily “correct” look using vrayscattervolume layered with some classic fresnel opacity mapped spheres to provide a blue high-alititude fade off into space. its not perfect, but holds up ok unless you study the edges too closely. ill also have to forget about going into the atmosphere, but then the maps would fall apart if i got that close anyway.
ive also done my hacky distance-tex driven cloud colour changes. currently takes about 20 mins a frame at 4k on my 3990x.. im hoping to cut that in half with some tweaks.
i would love to improve the “fluffiness” of the clouds, since just using the nasa cloud texture for displacement doesnt give the best effect…
ideally i would use the texture to drive a volumegrid based procedural cloud setup for proper 3d fluffy clouds… but it would take weeks to get reasonable looking and probably take the same amount of time a frame to render.
if i have more spare time (unlikey) i guess i might be able to do something with scattervolume, but im guessing that would require creating actual geometry to texture, which would be an absolute killer.
VolumeGrid DOES work with IPR, but you have to set your renderer to GPU first. Not sure why, or if this is a bug.
For the clouds perhaps you could threshold the clouds and then use a noise texture for bump or displacement using the clouds as a mask.
What you have looks pretty nice, better than 90% of planet renders out there in film/TV.
How did you get the sharp terminator effect (LightWave use to have a Sharp terminator option, just for this)? Or is just from the large scale and small lightsource? What is the light source?
You could always render a simple sphere with the light in a slightly different position (or wider light source) and then use this to comp a blue haze past the terminator for a bit of a scatter effect. Generally for something like this I would do a lot of it in the post because it is faster and more controllable, also easy to change if you or a client changes their mind (rare, I know).
So your shot is going from a wide like this right through the atmosphere to the surface?
at the moment the shots are likely to stay in orbit.. however the idea is to make the model as flexible as possible for potential follow up work from the same client.
I’m using Vrayscattervolume material now and cannot see any opacity map still. Is this going to be implemented at all? Right now I’m creating a cloud layer at fairly low altitude, using a cloud map and some vraydisplacement. It looks fairly good but because there is no opacity map it really affects the underlying layers.