The Flakes 2 material can be used to add metallic flakes to a material. It works by simulating at render time the aggregated effect of a large number of mirror-like flakes scattered over the surface of an object. An example use is blending (using a V-Ray Blend Mtl) a V-Ray Mtl with enabled Metalness with a V-Ray Flakes 2 Mtl will create a similar result to a Car Paint 2 Mtl, but give you more control over the look of the shader, as the two layers are whole separate material nodes with more controllable parameters.  The Flakes 2 Mtl uses GGX distribution which makes it fast and memory efficient.

This section lists input sockets that are not found in the Properties tab but only as inputs for the node.

Flake Random Color – Sets colors from the specified map node to the flakes in a random pattern. Only the bottom row on the u-axis of the map is sampled for colors.

Flake Uvwgen – Allows connecting a texture placement node.

Flake Color – Specifies the color or map of the metal flakes.

Flake Orientation – Specifies the orientation value or map of the metal flakes. The orientation of the flakes is relative to the surface normal. When this value is 0.0, all flakes are perfectly aligned with the surface. When set to 1.0, the flakes are rotated completely randomly with respect to the normal. Values above 0.5 are not recommended, as they can produce artifacts. An integer node can also be connected to this option.

Flake Orientation Tail – Controls the transition from highlighted areas to non-highlighted areas.

Flake Glossiness – Specifies the reflection glossiness value of the flakes.

Flake Density – Specifies the density (number of flakes) for a certain area. Lower values produce less flakes, and higher values produce more flakes. When set to 0.0, it produces a material without flakes. 

Flake Scale – Scales the entire flake structure.

Flake Scale Triplanar – Active only when Mapping Type is set to Triplanar. Scales the entire flake structure.

Flake Size – Specifies the size of the flakes relative to the distance between them. Higher values produce bigger flakes, and lower values produce smaller flakes.

Flake Map Size – Internally, the material creates several bitmaps to store the generated flakes. This parameter determines the size of the bitmaps. Lower values reduce RAM usage, but may produce noticeable tiling in the flake structure. Higher values require more RAM, but tiling is reduced.

Flake Seed – Specifies the random seed for the flakes. Changing this produces different flake patterns.

Mapping Type – Specifies the method for mapping the flakes. The possible values are:

Mapping channel – The flakes are mapped using the specified channel.
Triplanar – The material automatically computes mapping coordinates in object space based on the surface normals.

Mapping Channel –  Specifies the mapping channel for the flakes when the Flake mapping type is set to Mapping channel.

These options are inactive with V-Ray GPU enginе.

Trace Reflections – Global switch to toggle reflections for the flakes.

Trace Depth – Specifies the number of times a ray can be reflected.

Double Sided – When enabled, the material is double-sided.

Cutoff Threshold – Specifies the cutoff threshold for the reflections of the different layers. 

Use Environment Override – When enabled, allows you to specify a local environment map for reflections and refractions.

Environment Override – Specifies a map for the environment override. 

Environment Priority – Specifies the environment priority for the Environment Override texture for this material.