Cycles realistic atmosphere (with scattering)


(Atair) #21

people requested the file - here is the dropbox link: https://www.dropbox.com/s/ut0jmzkltfoyaml/Atmosphere05_ani02Packed.blend?dl=0

haven’t looked at it in a while, but all should be there


(smilebags) #22

This looks wonderful - I attempted the same thing with acceptable results but you’re getting much stronger ‘sunset’ colours than I did. Very nice work.


(CPLTarun) #23

Wow you guys, this is a treasure trove. Thanks so much Atair. I’ve been trying to make a photo realistic Earth for a while now, but I’m not that technically savy with Cycles nodes, so the screencaps and blend files really help. Kudos! :slight_smile:


(macio) #24

The link doesn’t work
Anyway, impressive work


(Atair) #25

i updated the link on the fist post, should not expire this time…


(jetamac) #26

I think it expired again, getting a 404 message. Any chance you would update the link? It’s such a great effect, and I’m having a doozy of a time trying to make it work on my own (very, very new to blender!) Thanks for your time!


(Nitram_2000) #27

I too would appreciate a reupload.

I shoot a lot of day to night timelapses and I’m considering trying to do some fake ones in Blender. I was super happy to read here that the lovely reds come through naturally. Such smart folks, those Blender programmers :slight_smile:


(Letuce) #28

I realize that this thread is really old, but the link isn’t working and you’ve achieved something I could really use.
I even tried placing the nodes as you have, but doesn’t seem to work.


(Atair) #29

uploaded the file to the forum, but no textures
(first post)


(pixelgrip) #30

here my try, with a modified version from this threat.i added a shader for rayleigh scattering, and a shader for mie scattering, and a shader for ozone absorption,with scattering coefficents from papers.i am not sure about the densitys for cycles.


(smilebags) #31

I believe 1m of a volume with a density of 1 will absorb the amount in each channel specified. Not sure about how scattering density works though.


(smilebags) #32

It seems like you’re missing the density falloff as the atmosphere thins?


(pixelgrip) #33

Brecht sayed in the dev update thread,that the absorption values ,ie the colors are peer Blender unit or m.

no the atmospheric thins are there,but they appering to dense in the outside renderings,i need to have a look at the atmosphereic height calculation,or better his positions.i have made the calculations for this allready.

for example 8000 meter for rayleigh scatter and 1200m for mie scatter. e ^-(h/8000)

edit,but i am not sure about the density value if its m³ or blender unit too or based on how big the volume is.


(pixelgrip) #34

a new render, with more visible falloff.no coloramp coloration,only scattering and absorption coefficents.

edit,and another render with some tweaked settings

edit,i added a moon with proportional real scale size and distance from earth.


(IDSG) #35

What ??? :dizzy_face::dizzy_face::dizzy_face: This is so beautiful !!! Very very good job ! Ambient light change just on sun moving ! Very very impressive ! :open_mouth::open_mouth: :drooling_face: :drooling_face: I love it ! :heart_eyes:


(burnin) #36

border looks too distinct

a photo, falloff for reference (also distortion cause by IOR can be observed)

and many, many more…


(pixelgrip) #37

my camera in the renderings was outside above the atmosphere,and sun angle from the side.your foto is taken with sun from behind the camera and within the thin atmosphere.the sun angle and the camera position,especialy the height,gives many different looks.

thanks,IDSG

here a new render and camera trough/within the thin atmosphere,sun from the side.


(burnin) #38

Yup, am well aware of that.

As mentioned before already, falloff is off :wink: it’s just not enough of it, the borderline is too strong, and on that note i threw in IOR remark assuming, you’re interested in perfecting, also mimicking the air (atmosphere) bending light.

If it matters, it was a special moment – “Full moon partially obscured by atmosphere.jpg” was taken on 21 December 1999 15:15:15 from aboard of shuttle Discovery somewhere between 570~612 km in orbit (servicing Hubble telescope)

Keep it up.
:slight_smile:


(pixelgrip) #39

I am not sure how this IOR effect is builded.since the IOR of air is just 1.000293 at STP,i guess its even less the thinner the atmosphere gets,and in space the IOR is vacum 1.

perfecting.so far i have avoided ,to make a custum falloff with the colorramp,to keep it linear and the math like in the papers.

the densitys are still not clear to me.i have used the basic formula 1/scattercoefficent,to get a density of 1 for mie scatter and rayleigh scatter.and this with a exp falloff from the papers.

the numbers of air molecules are (i have to look in the papers) 2.55 E ^ 25 / m³,if iirc.a huge number,and since cycles dont calculating molecules,i am guess this number isnt very helpfull at all.

maybe someone have a better idea,to make a molecules to cycles density converting math.
every idea is welcome.

btw Atairs results with just 2 colorramps are fantasic,for its simplicity.


(pixelgrip) #40

i have placed the camera 600km above the earth surface and in direction to the moon like the foto.with sun behind the camera too.for the ior effect ,i need some compositing tricks ,simlar the heat effects tuts in the net,but this is not important for me atm.