Sauerbraten is an open source FPS game engine with built-in map editor. The developers of Sauerbraten are currently in the process of adding support for RPG games. Sauerbraten runs under Windows, Mac, and Linux.
We are evaluating Sauerbraten for use in building Mythic.
To run Sauerbraten, your hardware must satisfy the following requirements:
Sauerbraten uses a "6-directional heightfield (or octree) world model." See the comment in the Horde3D forums.
The project Platinum Arts Sandbox 3D Game Maker is based on Sauerbraten.
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