Basic Earth Advice

racarate

Hi, I am starting to get into planetary rendering, and the first thing I tried was naturally our home planet.  



Since I'm just starting out, I just grabbed the Blue Marble image from NASA and blended in a constant blue glow based on Schlick Fresnel at the edges.  I then placed a point light at (0,0,0) and aimed it straight down the Z-axis.  I am using Blinn-Phong specular.  I'm not really happy with the look, and I was wondering if anybody could point me the right direction.  It is hard to work to reference, because almost every image has cloud cover and I have no way to procedurally generate clouds and do not want a single static cloud image.  I noticed some people use a bump map for the landmasses but that doesn't make much sense to me.  How would see such small-scale shadows from outer space?  Anyways, I would love some advice!

P.S. Both gamma-correcting the output and diving Blue Marble albedo by PI gave me strange results, so I am using a non-linear pipeline.

almighty_gir

One neat thing you could look into, is Raleigh Scattering. So you get an effect where if you look at the earth from a perpendicular angle to the light, the atmosphere would start to tint toward red.

Here's some great reference:
http://twistedsifter.com/2015/04/earth-day-gallery-by-nasa/

It would appear that the closer you get, and the more glancing the viewing angle, the more shadows are apparent. So i would maybe try rendering in 3 passes (or use some form of hacked parallax to achieve the same result)... A simple format for this would be to have, for example... a sphere for the planet, another every so slightly larger, which has the cloud texture multiplied to zero, and then another a little bigger than that, with the cloud texture itself.