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title: "V-Ray Single"
canonical: "https://documentation.chaos.com/space/VRAYHOUDINI/113280194/V-Ray%20Single"
format: markdown
---
This page provides information on the MtlSingleBRDF material node. Overview This node enables a BRDF material to be double-sided. It also enables materials to be transparent except in the case of specific ray types. By default, all V-Ray  BRDFs  are connected to an automatically-generated  MtlSingleBRDF  in the  VRScene  before assignment to the  Node  plugin holding the geometry.  Node The MtlSingleBRDF node contains the following input: brdf  – Specifies the BRDF material that will be affected. Parameters Mode  – Specifies one of the following behaviors for the material: Single-sided  – The lighting on the 'outer' side of the material is computed. You can use this to achieve a fake translucent effect for thin objects like paper. Double-sided  – V-Ray flips the normal for back-facing surfaces with this material. Transparent For Camera Rays  – The material is not visible to camera rays. Transparent Except For Shadow Rays  – The material is invisible to all rays except for shadow rays. This allows it to still cast shadows. Transparent Except for Shadow/Refracted Rays  – The material is invisible to all rays except for shadow and refraction rays. This allows it to cast shadows and be seen in refractions. Filter  – Specifies a color filter to tint the material. Allow Negative Colors  – Enables the use of negative values in the color swatches of the connected BRDF. Env. Fog. Mode (USD)  – Sets up environment fog in Solaris/USD. A V-Ray EnvironmentFog node must be added to the usd_env_fog slot of the material. Download these  Test Scene files  to try the mode. Env. Fog  – The fog effect is applied as an environment fog in Solaris/USD.  Volume Fog  – The fog effect is applied to a specific object only in Solaris/USD.