Particle systems are used to create visual effects in real-time applications such as computer games. However, emitted particles are often transient and do not leave a lasting impact on a 3D scene. This thesis work presents a real-time method that enables GPU particle systems to paint meshes in a 3D scene as the result of particle collisions, thus adding detail to and leaving a lasting impact on a scene. The method uses screen space collision detection and a mapping from screen space to texture space of meshes to determine where to apply paint. The method was tested for its time complexity and how well it performed in scenarios similar to those found in computer games. The results shows that the method probably can be used in computer games. Performance and visual fidelity of the paint application is not directly dependent on the amount of simulated particles, but depends only on the complexity of the meshes and their texture mapping as wellas the resolution of the paint. It is concluded that the method is renderer agnostic and could be added to existing GPU particle systems and that other types of effects than those showed in the thesis could be achieved by using the method.