Research And Implementation Of Shader Simplification And Optimization

With the rapid development of computer graphics, computer graphics plays an important role in more and more fields, such as data visualization, virtual reality, computer animation and games and so on. In order to improve the quality of rendering images, people have continuing putting forward new patterns of illumination model and rendering algorithms to achieve high quality rendering results under the limited hardware conditions. Since programmable shaders came up in1980s, programmable shaders quickly became the high reliability and high expansion tools to depict the objects’material properties in the field of computer graphics.Due to the limitation of hardware at that time, the important roles of programmable shaders have not been well demonstrated, for that the implementation of programmable shaders occupy a lot of rendering time and can easily exceed the capacity of the computer hardware. With the development of computer hardware capabilities, programmable shaders are also increasingly evident in the field of computer graphics. In the field of off-line rendering realm, programmable shaders are divided into surface shaders, light shaders, volume shaders, displacement shaders and imager shaders; while in real-time rendering realms also have pixel shaders, vertex shaders and geometry shaders. However, in order to produce complex effects, executing programmable shaders in today’s hardware may be still beyond the hardware capabilities and result in long rendering time or rendering failure. Thus it is necessary to simplify and optimize the programmable shaders to meet the rendering requirements and the hardware constraints.Because the programmable shaders are codes written by shader programmers and the programmers’different coding experiences, even producing the same effect, the shader execution times can be still different. This is an important opportunity to simplify the generated programmable shaders. For another reason, since programmable shaders are sections of codes, we can also use the methods of simplifying codes to simplify them considering the characteristics of programmable shaders. The shading process is an important step in the rendering pipeline, optimizing the shading process can reduce the rendering time with no or little loss of rendering quality effectively. In this paper, we can optimize and accelerate the shading process conveniently under the support of the "A new method for visual media calculation".The main content of this paper is divided into three parts:1. Shader simplifications:The rendering engine involved is a RenderMan standard off-line rendering engine, which focuses on rendering high quality results. We simplify the five types of programmable shaders in RenderMan Shading Language.2. Control shader simplifications:Effective controls of simplification processes are very important. How to reduce the rendering time and guarantee the quality of rendering results after simplify shaders is a main focus of this paper.3. Shader optimization:Shader optimization means optimize the shading process in rendering engines. Since the shading stage is the most time consuming stage in the rendering pipeline, optimize shading process can effectively reduce the rendering time.This paper presents a novel way based on previous work to simplify programmable shaders and optimize shading process to reduce the rendering time and ensure the quality of the results under current hardware constraints.