Create with Primitives
Most of Gaea's Primitives fall into this category. They generate basic geological shapes that can then be processed and eroded to look like a realistic terrain. Procedural generation allows you to create an infinite number of variations from the same node.
Primitives expose a property called Seed. Changing this property randomizes the shape. This allows you to create multiple primitives that follow the same general paradigm but are distinctly different shapes.
Primitives come in two forms: basic Primitives and Geo Primitives.
By themselves, they only create basic shapes, but combined with other Primitives and processed properly with shape modifiers, Erosion, and Look Dev nodes, they can be transformed into realistic terrains.
Multiple Primitives can be put together using the Combine node. When multiple Primitives are combined, they can produce sophisticated shapes.
Geological Primitives, or Geo Primitives for short, are a more detailed, spefific type of creator node. One of the key aspects of the Geo Primitives is to provide shapes that require very little erosion.
While normal primitives create basic shapes, Geo Primitives create complete geological elements such as Ridge, Badlands, Dunes, Crater, and so on. This can be a very useful timesaver, as you get near-complete shapes with a single node.
This video continues in Color Production.
Hand Drawn Primitives
The Mask node can also act as a Primitive even though it is categorized as a Data Map in the toolbox. However, it will not process the shape you draw.
To import a heightfield in any major 32, 16, or 8 bit image format, create a File node and load the desired file. You can simply drag and drop a valid file on the graph and a File node will be created for you.
Importing Meshes and Geospatial Data
Support for importing meshes as heightmaps, and satellite data such as DEM, SRTM, and other formats will be available soon.