The Mix MaterialThe representation of the surface or volume properties of an object. mixes two materials. OctaneRender v2019.1 introduced the Composite Material, which is similar but mixes multiple materials.
Amount - Controls the mix amount between the 2 material inputs.
First Material - The first material input.
Second Material - The second material input.
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. - Displacement for the material surface.