The Composite material node mixes several materials using masks (figure 1). This is more efficient than using several chained Mix materials since a single mix materialUsed to mix any two material types. can only mix two materials together. If a mask is not connected, the material's Opacity is used. The first MaterialThe representation of the surface or volume properties of an object. pin becomes the base layer. (figure 1).
Figure 1: A Composite material node used to mix a red and blue Diffuse materialUsed for dull, non-reflecting materials or mesh emitters. with a Checks node as a mask
DisplacementThe process of utilizing a 2D texture map to generate 3D surface relief. As opposed to bump and normal mapping, Displacement mapping does not only provide the illusion of depth but it effectively displaces the actual geometric position of points over the textured surface. - This attribute can be used to add a displacement texture to the material.
Custom AOV - Writes a mask to the specified custom AOV.
Custom AOV Channel - Determines whether the custom AOV is written to a specific color channel (R, G, or B) or to all the color channels.
Material - The Material input. When several MaterialsA set of attributes or parameters that describe surface characteristics. are used, the first Material pin becomes the base layer.
Material Mask - Controls the Material’s opacity using an Input map. If a mask is not connected, the Material's opacity is used.
Garbage Can Icon - Used to delete a specific material input.
Add - Adds another material slot to the Composite material.
Virtual Material - Gives particles random materials. The main material is assigned to the particles. After that, you can create any number of additional materials by adding them to the Materials List. The particles are assigned materials according to the Virtual Material type chosen. If you select the Non-Permanent Object Material checkbox, materials will not stick to the particles.