一种面向视景仿真的快速环境贴图方法

A Fast Enviroment Mapping Technique for Visual Simulation

环境贴图是绘制物体表面漫反射和镜面反射效果的一种有效方法。为了把环境贴图应用于视景仿真中,实现场景对象的真实感绘制,首先从分析球面调和函数入手,提出了漫反射环境纹理图的快速计算方法;然后在研究镜面反射模型时,提出采用箱式滤波器代替Phong余弦函数滤波的方法,从而简化了镜面反射环境纹理图的滤波计算;最后在实现阶段,采用立方体环境纹理图表示场景光照环境,并对纹理图进行分级细化从而提高了绘制效率。实验表明,该方法在增强对象真实感的同时,其运算速度也能满足交互系统的需求,非常适合视景仿真应用。

Environment mapping is an effective technique to render diffuse and glossy reflections.To realize realistic rendering of the scene in applying environment mapping to scene simulation,an approach for fast calculating diffuse environment maps is proposed from an analysis of spherical harmonics.To simplify filtering of environment maps for glossy reflections,a cube map representation is used together with a simple box-filter instead of the Phong cosine kernel.In the end,fast rendering is achieved by generating a mip-map of the specular environment map.The experimental result shows that this technique not only renders realistic objects but also satisfies interactive requirements,so it is well-suited for visual simulation applications.