Multiresolution techniques for rain rendering in virtual environments

Virtual environments often include rain and other atmospheric phenomena which are difficult to simulate in real time. In the field of virtual reality a number of solutions have been proposed which offer realistic but costly rain systems. Our proposal consists in developing a solution to facilitate the creation of rain scenes and to reduce the cost of previous particle systems, while maintaining the realistic appearance of rain . This objective is accomplished by performing a suitable management of the particle system. We include level-of-detail techniques in order to adapt the number of particles, their location and their size according to the position of the observer and distance to the particles. The framework we propose is completely integrated within the GPU, thus offering a solution which is fast and efficient.