SDL: The Alias Scene Description Language > Scene Description Language Reference > DEFINITION Section >
use_wavefront_depth
This parameter is only relevant if depth files are written out during rendering. If turned to FALSE, then the depth file is the same Alias depth file it has always been. If this is set to TRUE, then a depth file that is suitable for Composer is written. This depth file is different from the standard Alias depth file, in that the depth is an unsigned short value that is normalized between the near and far clipping planes.