The builder
Paint
Paint decides what the ground is made of. Sculpt gives you the shape; Paint gives you the rock, grass, sand or mud lying on it.
The six verbs
Paint offers Texture, Blend, Auto, Colour, Wet and Dry. Texture lays the swatch you have selected. Blend mixes it into what is already there rather than replacing it. Colour paints the colour field instead of the material.
Wet and Dry work on how damp the surface reads, which is what makes a riverbank look like a riverbank rather than grass that happens to be next to water.
Swatches and brush settings
The panel opens with a grid of swatches — the materials this world has — and a colour field beneath it. Pick a swatch, then paint.
The same three sliders as Sculpt follow: Size, Strength and Falloff. There are also rows for the pattern’s turn and size, which control how the material is laid down rather than where.
Advanced
Advanced holds a Slope range, exactly as Sculpt does, so you can paint only the steep faces or only the flat ground.
It also holds a toggle called "Only where it already is". With it on, a stroke strengthens the material where that material is already present and leaves the rest alone — the fastest way to tidy an edge without redrawing it.