How it’s Done

I started with a standard ray marcher and a sphere. Then I implemented 3d perlin noise, and layered octaves of it on top of each other to create complex mountainous offsets. To get a smooth ocean, I union the noisy sphere with a normal sphere.

Colors

To color the terrain, I stuff a color return value into the terrain SDF. I calculate the height of the point relative to the ocean, and match it to a manually selected color scale of 15 different colors.

Finishing touches

To add some dazzle, I made some stars. If a ray doesn’t hit the planet, I hash the pixel coordinate for a unique random number generator that remains stable across frames. I choose with a low probability whether the pixel should become a star, and color it a random greyscale value if so.

Finally, I did a quick post-process bloom effect, to give the effect that the beaches are glowing.