Efficient visibility projection on spherical polar coordinates for shadow rendering using geometry shader.
Efficient visibility projection on spherical polar coordinates for shadow rendering using geometry shader.
复制标题
使用几何着色器在球极坐标上进行高效可见性投影以进行阴影渲染。
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
Shuangjiu Xiao
中科院分区：
文献类型：
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作者：
Lingchun Li;Xubo Yang;Shuangjiu Xiao
可见性预计算对于涉及软阴影的基于 PRT 的渲染至关重要。虽然图形硬件光栅化越来越多地用于计算大量预计算任务的可见性信息，但光栅化的线性特征使其不适应坐标系中的样本可见性，而笛卡尔坐标非线性映射到坐标系。随着DirectX 10框架中几何着色器的出现，这个问题可以得到解决。在本文中，我们通过 DirectX 10 管道内的几何着色器，提出了一种在 PRT 预计算阶段在球极坐标上进行可见性采样的有效解决方案。同时，引入了用于阴影渲染的球面重参数化方案，将光照、BRDF和可见度等球面函数映射到球面极坐标上。
Visibility precomputation has become essential for PRT-based rendering involving soft shadows. While graphic hardware rasterization has been increasingly used to compute visibility information for a mass of precomputation tasks, the linear feature of rasterization makes it unadaptive to sample visibility in a coordinates system, to which the Cartesian coordinates are non-linearly mapped. With the emergence of geometry shader in the framework of DirectX 10, this problem can be solved. In this paper, we present an efficient solution for visibility sampling on the spherical polar coordinates in the precomputation stage of PRT by means of the geometry shader within the DirectX 10 pipelines. In the mean time, a spherical reparameterization scheme is introduced for shadow rendering, under which spherical functions as lighting, BRDF and visibility are mapped onto the spherical polar coordinates.