屏幕空间微结构表面对象环境光遮挡算法

针对目前复杂微结构表面对象中环境光遮挡计算方法效率低下的缺点,提出一种基于屏幕空间的环境光遮挡计算方法.该算法利用离屏渲染技术,只针对视点所见的场景计算环境光遮挡.算法采用2遍渲染处理,第1遍得到场景的深度纹理,第2遍采用计算最大遮挡角度的方法来快速计算出环境光遮挡的大小;结合延迟着色等技术,可以快速绘制出整个场景的环境光遮挡情况.整个绘制算法在图像空间完成,较好地利用了GPU并行计算的特点,可呈现可变形物体在动态场景中的环境光遮挡效果.实验结果表明,与同类算法相比,该算法不需要预处理,环境光遮挡关系判断高效,绘制速度得到了很大的提升.

Ambient occlusion in screen-space for mesostructure objects

The objects with mesostructure surfaces have complex model structures, which result in low efficiency of ambient occlusion algorithms. To improve the rendering speed, a screen-based ambient occlusion method was proposed. By using off-screen technique, only the points which can be seen were to determine the occlusion. The algorithm has two render passes: First, the depth texture of the whole scene was obtained; At second pass, the effect of ambient occlusion could be quickly computed by finding the maximum of the block angle. The ambient occlusion of the whole scene could be rendered by the deferred shading technology. The algorithm runs entirely in image space, and uses graphics pipeline to show the ambient occlusion effect of deformable objects in dynamic scenes. Experimental results show that the proposed method is more efficient than the available methods, as this method doesn-t need any pre-processing, and the time used for ambient occlusion determination is less.