Mode – Gives the ability to switch between the Open PBR shading model and the V-Ray model. The Open PBR model differs in its structure from the V-Ray model. See more about the V-Ray Material Layers in the Render Theory article.

Color – The diffuse color of the material. Note that the actual diffuse color of the surface also depends on the reflection and refraction colors.

Texture – Specifies a texture file to be used for the diffuse color slot.

Mix Strength – Specifies a blend amount for the texture map.

Diffuse Roughness – Used to simulate rough surfaces or surfaces covered with dust (for example, skin or the surface of the Moon). See the Diffuse Roughness example for more information. A map can be attached to this slot.

Source – Specifies the source of the opacity for the material.

Default – The RGB channel from the currently attached texture is used for opacity. This is the default behavior.
Alpha from Texture – The alpha channel of the currently attached texture is used for opacity.
Alpha from Diffuse – The alpha channel of the texture attached in the Diffuse channel is used as opacity. This option saves additional steps when setting up materials: you can use the Diffuse channel to attach bitmaps with embedded alpha channel for both Diffuse and Opacity. It eliminates the need to use and add the same bitmap in the Opacity channel.

Color — Controls the transparency of the material where white is opaque, and black is fully transparent.

Texture – Specifies a texture file to be used for the opacity.

Mix Strength – Specifies a blend amount between the texture map and the color.

Color – The self-illumination color of the material.

Brightness – Specifies a multiplier for the self-illumination Color. This is useful for boosting the self-illumination values so that the surface produces stronger illumination with GI.

Texture – Specifies a texture file to be used for the color of the self-illumination.

Mix Strength – Specifies a blend amount between the texture map and the color.

Mix Type – Specifies how the texture map and the color mix.

Normal – Stacks the texture map on top of the Color. This is the default.
Add – Adds the texture map to the Color.
Subtract – Subtracts the texture map from the Color.
Multiply – Multiplies the texture map by the Color.

Self-Illumination Affects GI – When enabled, the self-illumination affects global illumination rays and allows the surface to cast light on nearby objects. Note, however, that it may be more efficient to use area lights or VRayLightMtl material for this effect. 

Compensate Camera Exposure – When enabled, the intensity of the Self-Illumination is adjusted to compensate the exposure correction from the VRayPhysicalCamera.