We present a real-time simulation of spray painting incorporated into a VR environment as an alternative training system for ship-building industries. The system allows the user to try out a painting work on life-size structures with a spray gun. Our goal is to provide a trainee realistic painting experience in real-time as well as to represent the thickness of the deposited paint on the surface for evaluation of his performance. The Gaussian model is used for a painting deposition model, and texture mapping technique is utilized to provide efficient visual feedback. We also present effective collision detection methods for a volume of spray paint particles