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title: "V-Ray Surface Luminance"
canonical: "https://documentation.chaos.com/space/VRAYHOUDINI/113280030/V-Ray%20Surface%20Luminance"
format: markdown
---
This page provides information about the V-Ray Surface Luminance Texture. Overview V-Ray's extra attributes for the Surface Luminance node allow control of luminance calculation. The most common workflow for the Surface Luminance node attributes is to connect the node to a floating texture input slot of a  V-Ray ExtraTex  render element. This way you can control the Luminance mode showing in the ExtraTex channel.  Parameters Mode  – Controls how luminance is calculated. No Luminance  – No luminance is calculated. Direct Light  – Calculates luminance from direct lighting. It creates a grayscale mask over the points of objects lit by direct lighting. Diffuse Light  – Calculates luminance from indirect lighting (GI). It creates a grayscale mask over the points of objects lit by indirect lighting.  Direct+Diffuse Light  – Calculates luminance from direct and indirect lighting. This creates a grayscale mask over the points of objects by direct and indirect lighting. Samples  – Specifies samples for diffuse lightning. Contribute   to   GI  – When enabled, the direct light contributes to the GI calculations. The effect is visible only when the texture is used for diffuse calculation with either the  Diffuse Only  or the  Direct+Diffuse  mode.