World and levels › Terrain
Gaea: first steps
Know first: Landscape: terrain from a heightmap, What real land looks like
Gaea is a terrain generator: you build land from nodes, small blocks that each do one job, connected into a chain called a graph. This flow takes you from an empty graph to a first terrain you can send to a game engine. It’s a piece of land about 1 km across with a mountain and hills, eroded by water, built and exported as a heightmap. On the way you’ll set the size in meters, connect a few nodes, check heights, and write down the numbers that the import into Unreal needs.
Goal
Before: an empty graph in Gaea 2. After: a 16-bit PNG heightmap, 1009 × 1009 pixels, of a terrain 1008 m wide with a height range of 512 m. It holds a mountain with hills around it, shaped by erosion, and comes with a short note of its size. With that note, the flow From a generator into the engine brings it into Unreal with meters intact.
Why these numbers? Unreal builds a terrain from a grid of vertices, points that hold heights, and it prefers grids of 1009, 2017, 4033 or 8129 vertices per side. Between 1009 vertices there are 1008 gaps, so at 1 m per gap they span 1008 m. Gaea works in pixels: 1024 pixels across 1008 m is about 0.98 m per pixel. The Unreal node at the end of the graph resamples them to 1009 vertices, exactly 1 m apart. And a height range of 512 m matches Unreal’s default vertical scale of 100 without extra math.