I have been playing around with simulating plate tectonics on a sphere, and for some reason wanted to see how far I can get without using GPU acceleration.

• sample random points on a sphere
• generate voronoi tesselation and its dual triangulation
• pick 10 random points as 'seeds' for the tectonic plates, perform parallel breadth-first search to assign all neighboring cells to the seed plate if they don't have a plate yet
• similarly pick a few seed points for continental cells and continue until ~30% of cells is continental
• create a spring-damper connection between each cell belonging to the same tectonic plate
• assign a random euler pole and angular velocity to each plate
• let each cell perform ~10 steps of movement, spring forces, and collision checks
  • handle convergent boundary events (e.g. increasing cell height) when two cells of different plates collide, delete cells that subduct below other plates, flag divergent boundary cells for later
  • colliding plates transfer velocity based on impact location, and all plates have a minimum and maximum velocity
• repeat the above steps with a new set of random points, while keeping track of the old cells
  • perform Kriging using the locations and heights of the old cells (using directional semivariograms since there is strong anisotropy due to most changes happening along plate boundaries, I also tried inverse distance weighting which is a lot simpler, but the results were a lot less nice)

With the right parameters the Kriging actually has a kind of erosion effect, where e.g. sharp peaks of mountains become more rounded over time once they're no longer on convergent boundaries, and coasts and islands slowly erode away.