Abstract
3D Graphics on mobile devices has been an arising requirement in recent years. Some application programs are developed with graphics library like miniGL[4] or PocketGL[6], which are based on traditional graphics pipeline. Due to insufficient computation power of mobile devices, it is difficult to run traditional graphics pipeline as smooth as on desktop PC. The memory capacity presents another problem when holding large scale models. In this paper, we propose a client-server based rendering mechanism to replace the traditional graphics pipeline. Within this mechanism, the scene (model) is rendered on desktop PC (server) by OpenGL[5], then the rendering result is sent to mobile devices (client). The post-rendering on mobile devices is constructed by an image based rendering(IBR) method, which is called 3D Image Warping[2][3]. Artifacts may occur when using 3D image warping. To solve this, we also implement a simple splatting[7][9] method which consumes a little more extra computation power but provides satisfactory image quality. Besides, to improve frame rate, floating-point numbers computations are replaced by fixed-point computations. The mobile devices used in our system are Microsoft WinCE based PocketPC, with 206 Mhz StrongArm processors. The frame rate is about 4.5 when splatting is off and 4 when on for output image size of 240 by 180.