基于局部复杂度的环境遮挡

摘要

To accelerate the rendering by screen space ambient occlusion (SSAO), we propose a novel method by exploiting the frame-to-frame coherence for local complexity. The basic idea is to design a local complexity for each pixel, and the pixels with similar local complexity have similar AO values. Thus, for a pixel in the current frame, its AO value can be obtained by reusing the AO value of the pixels in the previous frames that have similar local complexity, based on the frame coherence. In this way, much computation can be saved for acceleration. Moreover, we give a measure to avoid accumulation errors in reusing AO values. Experimental results show that our algorithm can improve the performance of SSAO by 10~40 percent without lowering the rendering quality.%为了提高基于屏幕空间的环境遮挡算法(SSAO)的渲染速度,利用局部复杂度的帧间连续性,提出一种SSAO加速算法。首先为每个像素定义局部复杂度,其中局部复杂度相似的像素会有近似的环境遮挡(AO)值；在此基础上,利用帧间相关性,对于当前帧的像素 p,若能在前几帧中找到与它有近似局部复杂度的某个像素,则可以直接复用前面帧的像素的AO值而无需重新计算；最后针对AO复用过程中产生的累积误差提出一种避免误差的方法。实验结果表明,在不影响效果的情况下,该算法可以将SSAO的渲染速度提高10%~40%。