Wrapper

Image RemovedImage AddedThis node can be used to specify additional surface properties per material.

Base Material - this is the actual surface material. 

Alpha contribution Tex - determines the appearance of the object in the alpha channel of the rendered image. A value of 1.0 means the alpha channel will be derived from the transparency of the base material. A value of 0.0 means the object will not appear in the alpha channel at all and will show the alpha of the objects behind it. A value of -1.0 means that the transparency of the base material will cut out from the alpha of the objects behind. Matte objects are typically given an alpha contribution of -1.0. Note that this option is independent of the Matte surface option (i.e. a surface can have an alpha contribution of -1.0 without being a matte surface).

Generate GI -  a multiplier for the amount GI generated by the material.

Receive GI -  a multiplier for the amount GI received by the material.

Generate Caustics - a multiplier for the amount of Caustics generated by the material.

Receive Caustics -  a multiplier for the amount Caustics received by the material.

GI Quality Multiplier. - a multiplier that allows you to control the GI sampling of the current material. Values bigger than 1 increase the sampling for the particular material while values smaller than 1 decrease it.