Dirt Maps

GTA V uses a so-called dirt map to generate dirt effects on vehicles' exterior. This guide explains how a dirt map is set up.

Textures

A dirt map contains three textures. Each texture is a seperate greyscale texture saved in one RGB channel:

Combined dirt map with all RGB channels Red Channel Green Channel Blue Channel

• Red: Applies dirt effects while roads are dry.
• Green: Decreases specularity. By default it's a high contrast version of the red channel.
• Blue: Applies dirt effects while roads are wet.

The diffuse will be applied as a brown overlay on top of the surface. Lighter areas on each channel will have a stronger effect, darker areas a weaker effect. Black will have no effect at all.

Mapping a dirt map

By default, the game uses one shared dirt map for all cars. Some mod authors also use custom dirt maps made for specific vehicles for better looking results.