环境贴图在VR系统中的应用研究

为了把环境贴图应用于VR系统中，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。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。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，该方法实现了物体漫反射和镜面反射的快速绘制，非常适合虚拟现实应用。

Application study of environment mapping in VR systems

To realize the realistic rendering of the scene in applying environment mapping to VR systems, an approach to fast calculating diffuse environment maps was proposed starting from the analysis of spherical harmonics. To simplify the filtering of environment maps for glossy reflections, we decided to use a cube map representation together with a simple box-filter instead of the Phong cosine kernel. In the end, we achieved fast rendering by generating a mip-map of the specular environment map. The experimental result shows that this technique realizes fast rendering of diffuse and glossy reflections and is well-suited for virtual reality applications.