The material tweaker is a combination of the Material Booster and the Material Blender.

It splits up the material into the component channels and allows you to boost them (changing their contribution to the material) as well as changing their colours using blend modes.

• Material Transparency Activate this is the material contains transparencies and you would like those be evaluated for radiosity.
• Camera Rays Only Only applies the node if the current spot is directly visible by the camera.