r_Log

Logs rendering information to Direct3DLog.txt.
Use negative values to log a single frame.
Usage: r_Log +/-[0/1/2/3/4]
	1: Logs a list of all shaders without profile info.
	2: Log contains a list of all shaders with profile info.
	3: Logs all API function calls.
	4: Highly detailed pipeline log, including all passes,
			states, lights and pixel/vertex shaders.
Default is 0 (off). Use this function carefully, because
log files grow very quickly.