Crash, Falling and Flying Icons 3D screensavers are based on SimulDeck 1.0 engine. SimulDeck engine contains collisions detection core and physics core, which makes engine able to simulate real physics conditions. Engine maintenance all three Newton's Laws of Motion. SimulDeck can simulate events as falling objects with various gravitation acceleration, objects collisions with respect to their mass and coefficient of restitution, friction and much more. Collision detection is based on sphere-tree bounding technique, which is fast and suitable for real-time simulations.