renderdl reads a file containing scene description commands and “executes” them. Such files are commonly called RIB files (RIB stands for RenderMan Interface Bytestream). There are two kinds of RIB files: ASCII encoded RIB files and binary encoded RIB files. A binary RIB file is smaller than its ASCII encoded equivalent, but an ASCII RIB file has the advantage of being editable in any text editor or word processor.
To render a RIB named file.rib, just type:
renderdl file.rib
It is possible to render more than one file:
renderdl file1.rib file2.rib file3.rib
In this case, renderdl reads each file one after the other, and the graphic state is retained from one file to another (in other words, the graphic state at the end of one file is the starting graphic state for the next file). If a file cannot be found, it is simply skipped. This behaviour is useful to separate the actual scene description from rendering options. For example:
renderdl slow_options.rib scene.rib renderdl fast_options.rib scene.rib
These render the scene scene.rib twice but with different rendering options. slow_options.rib contains options for high quality rendering such as low ShadingRate and high PixelSamples, and fast_options.rib contains low quality (speedy) option settings.
If no file name is specified, renderdl reads scene description commands from the standard in. This feature enables piping commands directly in renderdl. For example, to enter scene description commands interactively (which is not really practical), do the following:
renderdl Reading (stdin) <enter commands here>
If you wish to pipe the content of file.rib in renderdl, type:
cat file.rib | renderdl