V-Ray Material Bump

Bump Map – Allows you to select a texture for the bump or normal map. Leaving this unconnected turns off bump/normal mapping.

Bump Amount – A multiplier for the bump map effect.

Bump Type – Determines how the Map parameter is interpreted.

Bump map – Applies the map as a bump map.
Normal Map in Tangent Space – Applies the map as a normal map in tangent space.
Normal Map in Object Space – Applies the map as a normal map in object space.
Normal Map in Screen Space – Applies the map as a normal map in screen/camera space.
Normal Map in World Space – Applies the map as a normal map in world space.
From Texture Bump Output – The map is applied as determined by map type itself.
Explicit Normal – Applies the map as an explicit normal.