SurfaceCover

biotareadonly

How much of the ground something is growing on, 0..1.

The pigment of a biosphere, laid where the temperature, the air and the rainfall allow it. The design bible's flora is post-MVP; this is the color it leaves on the ground when it arrives, and the reason a temperate world reads as one from orbit rather than as a wet desert.

brightreadonly

Impact-fresh material: crater rays and the continuous ejecta blanket.

The one high-contrast albedo feature an airless world has, and the reason the Moon does not read as a uniform ball. See rayBrightness.

darkreadonly

Flood basalt: the dark, smooth plains that pond in basins.

Mare against highland is the largest albedo contrast on the Moon — a factor of two — and it is invisible to geometry, because a flooded basin floor is exactly as flat and as low as an unflooded one. What decides it is whether melt reached the surface there, which is the body's volcanic history and a basin deep enough to crack the crust.

icereadonly

Condensed volatiles lying on the surface: caps, frost, an icy shell.

mineralreadonly

Where this crust sits on the body's own compositional ramp, 0.5 neutral.

One scalar rather than a color because the ends of the ramp are a property of the body — Mars runs dust-ochre to basalt-gray, Europa runs clean ice to sulfur-stained — and only the position along it is a property of the ground.

wetreadonly

Standing liquid in a channel: the riverbed drainageCarve floored.

A river is not in the height field — the field says where the valley floor is, and this says whether liquid is running along it. The material draws it as the sea is drawn, and it is the one channel that can put water above the sea datum.