The Clamp texture provides a Minimum and Maximum value to clamp the values of an incoming Texture map. In Figure 1, the material shows a Marble Texture passing through a Clamp texture, and then it connects to a DiffuseAmount of diffusion, or the reflection of light photons at different angles from an uneven or granular surface. Used for dull, non-reflecting materials or mesh emitters. material's Diffuse channel. The Clamp values are set to a Minimum of 0.0 and a Maximum of 0.2. The result has filtered out the high values of the original Texture map.
Figure 1: The Clamp texture alters the values of incoming textures