About XTerra

XTerra is Graphics Engine for Real-Time rendering of terrain. It is an implementation of an algorithm introduced in 1998, by Ruttger et al., for fast generation of multiple levels of detail for height-fields. While far from completion, XTerra is currently at a stage where it can load and render very large databases on a generic, home-user PCs. The engine is fully open-source, and improvements are appreciated by the author. The lateset release and its source can be downloaded from the main page.

Before running the program

Please make sure you read the following before running the program.

System requirements:

• Windows operating system
• 20 megabytes of free memory
• OpenGL-compatible graphics card
• GLUT 3.7 beta installed

The keys:

W/S - Forward/backward

A/D - Yaw left/right

C/V - Pitch up/down

1/2 - Polygons/wirefame

3/4 - Skybox on/off

+/- - Increase/decrease polygon count

P - Exit the program

\ - Take a screen-shot (raw RGB file)

Emergency Procedures

• Help! The program has gone out of control! The terrain is 'ticking' like mad!

Solution: This is a problem of the adaptive LOD mechanism. First of all, press the '-' key repeatedly. This may solve most of 'LOD-vertigos'. If this doesn't help, try to close background applications, the most CPU intensive first.

Last solution - compile the program without the A.L.O.D.M. that can be found in the main module, under 'void mainRenderScene () ). Comment out all the 'C = 's.

• There is a lot of vertex popping.

Solution: Increase triangle count (+ key)

• The program is slow.

Solution: Decrease triangle count (- key), turn-off the skybox (4 key)

To Do's

• Fix the god-damn clipping problem
• Refine the adaptive LOD mechanism
• I.NTERFACE
• Clean up the main.c module code a bit
• Add roll to the camera