This page provides information about the User Scalar utility texture in V-Ray for Blender.
Overview
The V-Ray User Scalar texture allows the user to read and return a single number value of the currently shaded object as a result. This can be useful if the same material or texture is applied to several objects in the scene, but we want to control some of its aspects (i.e., material glossiness or a blend between two other textures inside a Mix texture, etc.) with user-defined properties.
UI Path: ||V-Ray Node Editor|| > Shader > Add > Texture Utilities > V-Ray User Scalar
Properties
User Attribute – Specifies the name of the user attribute that is looked up and returned from this texture.
Default Value – Specifies the value to return if the user attribute is not found on the shaded object.