DEFINITION Section
The DEFINITION section contains definitions of all the entities that will be “instanced” later in the MODEL section, similar to declaring variables before using them in traditional programming languages.
The DEFINITION section is the place for definitions of:
The DEFINITION section begins with the word DEFINITION in all caps on a separate line with no punctuation. The section ends where the next section begins.
The DEFINITION section contains declarations of data items (see below for data types and syntax). The order in which items are defined is significant: declarations can only refer to variables that were defined previously in the text file.
The renderer is controlled by parameters in the SDL file. You can override many of the parameters in the SDL file with command-line options. These parameters are included in the DEFINITION section.
The name of the output file can be specified on the command line or included in the camera definition (since each camera outputs its own view of the scene). See the description of Camera data types for more information.