Generation Research Of Real-Time Shadow On Visual Simulation System In Train Driving Simulator

The real-time shadow rendering as one of the key technologies to increase third dimension of virtual scene has always been of concern, which makes computer-generated images more realistic. The shadow of the scene suggests the geometric information, such as object shape, the relationship of objects location , location and direction of light sources. In various types of simulators , large-scale three-dimensional games, geographic information systems and computer-aided design, manufacturing, many mature technology of shadow rendering has been widely used. However, rendering real-time shadow of dynamic scenes remains a challenge.In recent years, with the rapid development of computer graphics hardware, complex graphical computing has gradually shifted from the CPU to graphics hardware - GPU. The development of modern GPU technology has greatly promoted applications of computer real-time rendering technology , mainly including interactive graphical modeling procedures and virtual reality systems, as well as games, computer animation. Research of real-time shadow rendering based on Graphics hardware has acquired a great deal of results, and using programmable graphics hardware to accelerate and improve the rendering effect has become a major trend.In this paper, based on modern GPU's programmable features, learning from the advanced theories and technologies outcome of the three-dimensional computer graphics, computational geometry, scientific visualization, virtual reality, dynamic real-time shadow technology is researched and analysed in-depth. Comparing advantages and disadvantages of a variety of typical real-time shadow algorithms, according to high real-time demand of the train driving simulator, one algorithm is finally choosed to expand. Based on experiment, the image-based algorithm has been improved , and has good application in actual project. Compared with other algorithms, the algorithm has better balance between realism and real-time of shadow, and real-time interactive and realistic effect of the shadow meet the actual demand. Finally, this paper expects the development direction of real-time dynamic shadow in the future.