文件名称：Fixed function pipeline using vertex programs
文件大小：1MB
文件格式：PDF
更新时间：2013-12-18 16:42:20
Shader GPU
In year 2001 nVidia released its GeForce3 3D grapics card, which was the first 3D card to use a vertex processor. The vertex processor had the advantage over the hardcoded version, since it allowed direct access to the instruction set. The first chip used both a vertex processor and a hardcoded part, to provide backward-compatibility, but later 3D cards were released with only a programmable vertex processor. The backward-compatibility for a 3D card with only a vertex processor, is solved through the driver. Since the vertex programs replaces the fixed-function pipeline (FFP), the fixed-function pipeline for backward-compatibility must be implemented as vertex programs. The programmer accessing the FFP-functions will not see the underlying structure of vertex programs. The choice of 3D-API was the OpenGL 1.4 and its Vertex Program ARB extension. Implementing the vertex programs that should replace the FFP, requires knowledge of the FFP structure and mathematical operations in 3D graphics. A thorough prestudy was necessary to accomplish the task at hand. After the prestudy we defined some requirements. Because of time restrictions the focus was set on a subset of the defined requirements, which included transformation, lighting and correctness of the program. The program that was to be designed and implemented was a prototype, that generated a text string representing the vertex program. The testing was done pure visually, where the generated vertex program was tested against the non-vertex program functions of OpenGL. As expected, testing was succesful An evaluation and a conclution was made of the project. Despite some problems underway, the implementation functioned satisfactory. Improvements and extension of the program was also listed.