标题: | 手持型装置中三维绘图之彩现架构与模型传输 Rendering Architecture and Model Transmission for 3-D Graphics in Handheld Devices |
作者: | 梁伯嵩 Bor-Sung Liang 任建葳 Chein-Wei Jen 电子研究所 |
关键字: | 三维绘图;手持型装置;彩现架构;模型传输;延迟光源照明运算;索引式彩现;进场渐进式模型;3-D Graphics;Handheld devices;Rendering Architecture;Model Transmission;Deferred Lighting;Index Rendering;Entrance Progressive Model |
公开日期: | 2001 |
摘要: | 随着三维绘图应用的普及,在手持型装置中实现三维绘图彩现能力,将会是未来的潮流。因手持型装置中所配备的运算硬体资源较少,而且所能使用到的网路频宽也相对较低。因此我们需研发具运算效能的彩现架构与模型传输方式,以提供足以满足各项三维绘图应用需求的能力。在此论文中,我们深入探讨三维绘图彩现过程中资料流的特性,并考虑手持型装置所特有的状况,而研发出两类具有运算效能的三维绘图彩现架构,以及一种在网路环境下减少模型初始传输时的停滞感的方式。 我们研发的第一种三维绘图彩现架构,根基于延迟光源照明运算以及索引式彩现技术。这架构可以避免在隐藏的多边型与图点上做多余的运算,因而可以提高硬体的使用效能。经过模拟后,发现此架构在平涂着色法与高氏着色法中可以消去 10% ~ 70% 的光源照明运算,在冯氏着色法中可消去30% ~ 95%。除此之外,此架构可进一步减少彩现架构前级的几何转换量,若由 CPU 执行,约可消去 56.1% ~ 78.4% 的运算。而且此架构更可以将彩现运算的部分工作后延,如着色与纹理贴图的运算均可以移至扫瞄速率区域。由于在彩现运算与扫瞄输出两项工作时间中取得平衡,因而可进一步提升整体彩现速率。我们研发的第二种三维绘图彩现架构,利用三重伫列架构,实现延迟光源照明运算。此架构一样能因延迟光源照明运算来减少不必要的光源运算。相较于传统单一伫列的架构,此三重伫列的运算更可以有效的加速彩现运算。根据 cycle-true 模拟,此架构可以将彩现所需的时间,缩短至原先的 52.9%。在模型传输方面,我们研发了进场渐进式模型。此传输模式可以在模型尚未传输完之前,网路的 client端即可以开始绘出三维画面,而减少使用者等待的时间。模拟结果显示,在特定视角下,约只需接收到 24.2%~54% 的部分模型档案,client端即可以开始绘制画面,因而减少减少模型初始绘出前传输时的停滞感。 我们研发的两类三维绘图彩现架构,以及模型传输方式,可以在手持型装置中,有效的改善三维彩现的运算效能与模型传输的使用者观感。因此,我们在此论文中所提出架构与方法,将可有助于建立一个普及的行动三维彩现平台,以支援各项互动式的三维绘图应用。 3-D graphics applications have played an important role in multimedia systems. With the progressive of VLSI technologies, it is a future trend to equip handheld devices with 3-D graphics abilities. Because of relative low computing power and narrow network bandwidth in handheld devices, we need to explore efficient rendering architectures and model transmission methods to offer enough performance for various applications. In this dissertation, we investigate on the nature of data flows in 3-D rendering, and propose efficient methods to improve the performance of 3-D graphics in handheld devices, including two sorts of rendering architectures and one model transmission method. The first rendering architecture bases on our deferred lighting and index rendering techniques. It can reduce the unnecessary operations on invisible polygons and pixels to improve hardware utilization. By simulation, the result shows that index rendering can eliminate 10% ~ 70% lighting operations in flat and Gouraud shading, and 30% ~ 95% in Phong shading. Besides, this architecture can reduce equivalent CPU cost on geometry processing into 56.1% ~ 78.4% compared with traditional architectures. Furthermore, this architecture can move parts of rendering jobs (shading and texture mapping) into scan-out rate area to speeded up rendering, because of the balance on computing load. The second architecture is based on our deferred lighting technique and triple queue structure. The architecture benefits from deferred lighting to reduce lighting operations. Besides, since the queue can avoid pipeline stall to speedup rendering, the triple queue structure has better performance than the traditional single queue structure. By cycle-true simulation, the triple queue structure can reduce rendering cycles into 52.9%. For model transmission, we propose entrance progressive model (EPM). With the EPM, the handheld devices can render image in the halfway of model transmission, and therefore the initiation time is shortened. The simulation results show that the models can be rendered from a specific viewpoint when only 24.2%~54% of EPM files are transmitted, and hence the EPM can reduce the feeling of waiting in model transmission. In the dissertation, we proposed two architectures and one transmission method to improve the efficiency of rendering and model transmission in handheld devices. Therefore, the proposed techniques can be utilized to construct mobile rendering platforms to support widespread interactive 3-D graphics applications. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT900428006 http://hdl.handle.net/11536/68702 |
显示于类别: | Thesis |