This is a debugging or 'draft-quality' integrator that implements only the direct lighting portion of the light transport. It is not designed to produce 'final-quality' images. Since it doesn’t implement indirect lighting paths it cannot produce reflections, refractions, or other global illumination effects, nor can it handle any effects that require a volume integrator. @parameters
numLightSamples: Controls the number of light samples for direct illumination per camera hit point. The default is 4.
numBxdfSamples: Controls the number of Bxdf samples for direct illumination per camera hit point. The default is 4.