SDL is the Scene Description Language that is used by Alias renderers. An SDL file is a binary file that can be converted, using the command line utility bsdl, to a text file that contains all the information necessary to render a scene, including models, shaders, lights, and animation. Because they can be converted to text files, you can edit an SDL file using a text editor and SDL commands. Usually, however, you do not need to edit SDL files directly. Instead, the interactive modeling program streams data to the renderer.

There are, however, some cases where you may want to edit an SDL file:

• for absolute, mathematical control over scene elements such as models, animation paths, and shaders
• to modify a generated SDL file manually, or with another program
• to create new procedural effects using the general programming features of SDL.

By applying basic programming constructs to scene descriptions you can create useful and spectacular effects that would be tedious or impossible to create with the interactive modeler alone. You can also augment the dynamics and particle systems of the interactive modeler with the flexibility of the SDL programming language.

Once you have an SDL file describing a scene, you can then render it using one of the stand-alone renderers (see Use a command line rendering program). See the Scene Description Language online documentation for more information.