mental ray Architectural and Design Visualization Shader Library

58 2 Architectural MaterialGold, silver and copper, perhaps?2.6.2.9 Brushed MetalsBrushed metal is an interesting special case of metals. In some cases, creating a brushedmetal only takes turning down the refl gloss to a level where one receives a “very blurred”reflection. This is sufficient when the brushing direction is random or the brushes are toosmall to be visible even as an aggregate effect.For materials that have a clear brushing direction and/or where the actual brush strokes arevisible, creating a convincing look is a slightly more involved process.The tiny grooves in a brushed metal all work together to cause anisotropic reflections. Thiscan be illustrated by the following schematic, which simulates the brush grooves by actuallymodeling many tiny adjacent cylinders, shaded with a simple Phong shader: