This paper describes a technique for cloth simulation entirely implemented on the Graphics Processing Unit (GPU). The cloth model is based on a mass-spring system with Verlet integration. It uses velocity modification approach for both correcting the over-elongated springs and responding to collisions. The collision detection method uses ray tracing which is hardware accelerated on NVidia RTX graphics card. As a result dressing a virtual garment on a human body takes about 0.4 seconds. The simulation of layers of cloth draping on a rigid object is demonstrated in the results section.