Procedumon is a technical demo in Unity of a 3D environment that is procedurally generated around the player as the player moves around. The environment that is generated is a forest with rivers and height differences.
You can move around with the WASD keys.
The above image shows the generated part of the world from a distance. If the player moves out of the red rectangle that is slightly visible in the center of the image, a new part of the world is generated. When that happens, parts that are too far from the player are deleted because they are no longer needed.