Locks the AA_seed so that the sampling noise won't change with the frame number (avoiding the film grain look).
If enabled, autobump is visible in SSS. Enabling this option will take into account the effect that displacement_autobump has on the ray-traced BSSRDF's result. This helps capture the high-frequency details of the surface more accurately when using autobump.
Beware that enabling this option will triple shader evaluations with SSS, resulting in much longer render times.
Enables the "nested dielectrics" system for IOR tracking in scenes with adjacent dielectrics. Defaults to on.
Sets indirect specular blurring to reduce caustic noise. Setting to zero gives the most accurate but also noisy renders, while higher values blur caustics to reduce noise.