Raytrace, post processing and Photoshop tips: Making a Material ID layer mask for post processing.   Here we have a simple bathroom scene that we will create a Material/Object ID layer mask for better control of our post processing.   The goal is to have a simple way of selecting particular materials or objects in photoshop(or your favorite photo-editing software) for individual settings such as contrast or exposure. Particulars of importance will be denoted by ALL