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 while the car is dirty. 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.


Authors