Long way to go...

There's still so much that needs to be done to improve the quality of my CG Earth, and I've been exploring options and learning that I really don't have enough know-how to get there yet.

Clouds are the biggest challenge and I've never been happy with my solution, so I'm going back to the drawing board with them. It's a tough nut to crack so it might be a while before I can achieve a proper cloud-filled Earth.

Next, surface detail. Considering I'm using at best 500m/pixel data from BMNG, I began experimenting with adding fractal noise to the displacement and other channels in the hopes of being able to do more close-up shots.

Since I'm starting with a displacement map, just adding displacement noise without regard for the existing topography will result in very artificial output - the same way that simply combining multiple orders of fBm noise will not make a fractal landscape look natural. I'm convinced I need some kind erosion algorithm (fractal, hydraulic, thermal...) but I haven't been able to find any good reference on the subject.

Sometimes when I look up one subject, I find that I need to understand several other topics before I can proceed. Other times, one subject leads to several other related issues that I had not been aware of. There's so much to study, understand and implement that I have to become less of an artist and more a weekend programmer, mathematician and scientist. Gradually, I hope to summarize what I've learnt that is relevant to the CG Earth project within the pages of this blog.

Meanwhile, here's another WIP shot. It has subtly better atmosphere and surface detail than a similar shot I created last year.

2012 version with better terrain detail, specular (rivers) and atmospherics (no more volumetric hack).

2011 version, took some hacking to get it looking like this.