Open the 3D Viewport, press N to open the sidebar, and select the Terrain tab. Click Generate Terrain to create a new terrain object with the TerraScape Geometry Nodes modifier. The generated terrain can then be controlled through the settings exposed in the Modifier Properties panel.

In the TerraScape modifier, use the Preset dropdown to switch between the available procedural terrain generators: Mountain, Canyon, Landscape, Peaks, and Range. Each preset uses its own procedural noise and Voronoi setup.

The main modifier exposes the preset selector, while the detailed generation controls for each preset are located inside the Geometry Nodes editor. Open the Geometry Nodes editor and locate the corresponding preset's sub-group node. Its exposed sockets contain the noise, Voronoi, and other generation parameters that control the appearance of that preset.

Enable the Erosion toggle in the TerraScape modifier. TerraScape simulates particles moving across the terrain to carve erosion channels. The main controls are: Iterations — Number of simulation steps. Particle Count — Number of particles used in the simulation. Particle Size — Controls the width and depth of the carved channels. Multiplier — Controls the final depth of the erosion. Flow Intensity — Controls the downward movement of particles. Softness — Smooths the resulting erosion data. Seed — Randomizes the initial particle positions. Higher particle counts and iteration counts can increase calculation time.