The V-Ray Light Material is a special material provided with the V-Ray renderer. This material is generally used to produce self-illuminated surfaces. This material's light emission can be used as indirect, as well as direct, illumination in the scene.

This allows for light sources of any shape. The Light Material may even be assigned at the object level and at the face level to self-illuminate only portions of a mesh.

Light Color – This parameter controls the color of the light material. A Texture can also be applied and blended with the color, using the Mix Strength option.

Color multiplier – A multiplier for the Light Color. A Texture can also be applied and blended with the value, using the Mix Strength option. Determine how the two are blended using the Mix Type option.

Opacity – A color to use as opacity for the material. Note that making the material less opaque does not affect the intensity of the self-illumination color. This is so that you can create perfectly transparent materials that nevertheless still emit light. A Texture can also be applied and blended with the color, using the Mix Strength option.

Emit on back side – When enabled, makes the object emit light from its backside as well. If this is off, the back side of the material is rendered as black.

Compensate exposure – Used when rendering with the V-Ray Physical Camera. When enabled, the intensity of the material is adjusted to compensate for the camera exposure.

Multiply by opacity – When enabled, the color of the light material is multiplied by the opacity texture. Otherwise, the color and opacity act independently (so-called additive transparency).