Generated Planet
To start with the biomes are handled by having a struct that keeps track of a set of gradients for each distinct biome. A shader graph then looks at the y axis in relation to the min and max, how high the biome covers to and some extra factors to blend biomes. Even with such a simplistic approach it works quite well, a render of the biomes shaded as a single color can be seen in figure 1.
For the mesh itself it is all very similar to the endless terrain, 6 meshes are used in total each in a different direction. The vertex on each mesh ar calculated to wrap 1/6th of the sphere, that point is passed to a script to generate 3d perlin noise which I did not hand code. That value is then manipulated by a noise filter an layered with any additional noise filters we have applied.
I definitely still have more to learn about noise terrain generation but I think the next project I do in this area is going to be to do with hydraulic erosion so for now this project ends here.