render

Instructs YafRay how to render the scene. 

   <render camera_name="name" raydepth="2" bias="0.3" gamma="1" exposure="0" background_name="name" 
	AA_passes="2" AA_minsamples="2" AA_pixelwidth="1.5" AA_threshold="0.04">
	<outfile value="filename" />
	<save_alpha value="off" />
   </render>

camera_name: text
Names the camera to use to render the image. Any scene file can have multiple camera definitions, it is here that you define which one to render the scene with.
raydepth:
Number of "bounces" to do with each ray. Higher values will result in more reflections and is important for scenes with many shiny objects. Simpler scenes can get by with as few as 2 bounces.
bias: ???
gamma: 0.0 to 1.0
Lower values make the resulting scene darker. Higher makes it brighter.
exposure: 0.1 to ??
Similar to gamma this controls the resulting brightness of the image. It does not seem to result in as harsh a difference as gamma however. Values lower than 1.0 will darken the image. Values higher will brighten things.
background_name: background
Name of the background to apply.
outfile: filename
Name of the file to create. The default name is salida.tga.
save_alpha: filename
Directs yafray to save the tga with the alpha channel on.