Terragen - An artificial landscape generator

Terragen [1] is a scenery generator, created with the goal of generating photorealistic landscape images and animations. Terragen is free for personal, noncommercial use. Although Terragen is a continually evolving work-in-progress, it is already capable of near-photorealistic results for professional landscape visualisation, special effects, art and recreation. Terragen has been used in a variety of commercial applications including film, television and music videos, games and multimedia, books, magazines and print advertisements [2].

Since version 0.89x, it is possible to use the GPU cluster to render images using Terragen in a distributed fashion. The Terragen wrapper, the applaunch plugin that permits to launch any executable from the GPU framework and the plugin manager extension integrated in GPU were written by nanobit (Rene Tegel). An additional program is still required to merge frames together in a video, at the end.

GPU comes along with Terragen files installed under the directory sandbox. In directory binexec, an additional GPU wrapper program called earthsim.exe is able to download and upload files from a central FTP server, and to pass parameters to the main terragen.exe application stored in sandbox directory. Finally, the application launcher applaunch.dll will mediate between the main GPU application and earthsim.exe.

<aemdea fenestrae>'s capacitors while computing a virtual landscape frame. <aemdea fenestrae> is one of GPU's entry gates.

In the beginning, a launch command is issued to execute the GPU wrapper, either locally or globally as usual. The GPU wrapper earthsim.exe attempts to contact a FTP server and downloads configuration files for terrain, sun and camera position for all frames that compose the video. It then randomly decides to render one of the frames out of the available ones, and uploads back on the FTP server an empty image\_xxxx.lock file, to signal to other clients that frame xxxx is being computed, avoiding double work. Once the image is downloaded, the wrapper launches the true terragen.exe program and lets it compute in batch modus, minimized in a DOS box. The computation can take from minutes to hours, depending on the image resolution and on several other factors, including terrain files and water rendering. Finally, the computed image is uploaded to the FTP server and is available for further processing: for example, to be glued in a video.

• [1] Terragen is a trademark of PlanetSide Software
• [2] Taken from the Terragen homepage