Ultra-low power render-based collision detection for CPU/GPU systems

Smartphones have become powerful computing systems able to carry out complex tasks, such as web browsing, image processing and gaming, among others. Graphics animation applications such as 3D games represent a large percentage of downloaded applications for mobile devices and the trend is towards more complex and realistic scenes with accurate 3D physics simulations, like those in laptops and desktops. Collision detection (CD) is one of the main algorithms used in any physics kernel. However, real-time highly accurate CD is very expensive in terms of energy consumption and this parameter is of paramount importance for mobile devices since it has a direct effect on the autonomy of the system. In this work, we propose an energy-efficient, high-fidelity CD scheme that leverages some intermediate results of the rendering pipeline. It also adds a new and simple hardware block to the GPU pipeline that works in parallel with it and completes the remaining parts of the CD task with extremely low power consumption and more speed than traditional schemes. Using commercial Android applications, we show that our scheme reduces the energy consumption of the CD by 99.8% (i.e., 448× times smaller) on average. Furthermore, the execution time required for CD in our scheme is almost three orders of magnitude smaller (600× speedup) than the time required by a conventional technique executed in a CPU. These dramatic benefits are accompanied by a higher fidelity CD analysis (i.e., with finer granularity), which improves the quality and realism of the application.