3d Game Terrain Generation

Good looking terrains always adds to the realism of a 3d game. Some tools deal exclusively with terrain generation, while others help with laying out the scene.

Terragen - Windows, Mac; Free for non-commercial use until v1.0 released. Permits development of gorgeous terrains.

Leveller - Windows; Commercial. Heightfield modeler with a simple interface and a number of useful plug-ins. At time of writing, $99 for a license. Free demo available.

Robot Frog 3D - Windows, Mac, *nix; Free. This page presents an algorithm for generating heightmaps.

HME - Windows, Linux; Donationware. Simple heightmap editor with a paint-like interface.

FreeWorld3D - Windows, (Linux in development); Commercial ($20). A terrain editor, with heightmap editing tools (raise, lower, smooth, flatten), support for painting texture layers, generating shadows, placing meshes and custom entities, skyboxes, and more.

Advanced Landscape Editor - Windows; Commercial ($39.99). A really nice and easy to use terrain editor. It has a WYSIWYG interface and makes terrain editing a breeze. Very useful for creating height- and lightmaps.

Kashmir3D - Windows; Free.