What you are looking at. Every cell holds one of six materials. No heightmap and no terrain generator: there is a single energy function saying how much each material likes each neighbour and how each answers gravity, and the sampler repeatedly asks every cell what it should be given the cells around it. The strata, the pockets and the water table are consequences of that function. Nobody drew them, and changing one number in the chemistry changes all of them at once.

β is inverse temperature: low is hot and disordered, high is cold and ordered. It is the only dial that matters, and the three buttons beside it are three paths to a temperature rather than three destinations. Anneal cools slowly, so the field stays near equilibrium the whole way down and settles into large clean domains. Quench cools abruptly and freezes in whatever disorder happened to be there, giving a fine, defect-ridden structure. Melt goes the other way. The same energy function and the same destination temperature give visibly different worlds depending on the route, which is the point, and is why a description of a world has to say how long to settle as well as how cold, not just where to stop.

Where this model stops equilibrating. Measured on this kernel, a 64³ field reaches equilibrium in about 186 sweeps at β 0.80. Above roughly β 1.1 it does not reach it at all inside any budget you will wait for: what you get then is a frozen configuration, not a sample from the distribution. Both are legitimate things to want. Only one of them is what "a sample" means, and the difference is invisible in the picture, which is why it is worth knowing before you trust one.

Measure rate reports site-updates per second. It drains the GPU queue before dividing, which sounds like a detail and is not: submitting work does not mean it finished, and measuring frames per second instead of completed work once overstated this same kernel by a factor of twenty-nine. The number here is work that finished.

The same kernel, driven by a message rather than by these sliders, is at the solid receiver; the world you can walk around in is here; and what a conforming implementation has to agree on is written down in the specification.