Research On Screen Space Ambient Light Occlusion Algorithm

Global illumination technology is an important technology of realistic graphics rendering.The traditional global illumination model is based on the physical optical transmission model,which can achieve very realistic effect on the rendering effect,but its computational complexity is very high.For some real-time graphics Application is no longer applicable.Real-time global illumination is a technology that has developed more rapidly in recent years,It starts from the components of the global illumination,through some special skills to approximate the effect of global illumination,ambient occlusion is one of the representative of the technology,it determine the occlusion of the object by calculating the geometric information around the scene object to,it can render very close to the real contact shadow effect,the computational complexity compared to the traditional global lighting technology is much lower.But the technology still can not meet the real-time requirements,which people put forward a variety of environmental light shielding improved algorithm.Screen space ambient occlusion(SSAO)algorithm is one of the most effective real-time global illumination algorithms,and is widely used in real-time 3D programs such as games.In this paper,the principle of SSAO is analyzed in detail,and its implementation process is given.For the sampling problem and the repeated calculation problem in the rendering process,the SSAO is optimized by combining the delay rendering technique and the improved AO calculation method.Which is representative of the use of inter-frame correlation TSSAO algorithm.Because of the sampling process caused by the noise problem,usually using Gaussian filtering and bilateral filtering for smoothing,but these two methods have their own shortcomings,Gaussian filtering for the edge of the part can not be a good reservation,rendering effect is not good,bilateral filtering although the edge of the problem is better,but in terms of operational efficiency is poor.The guided filtering technology is superior to the former two in the processing and calculation efficiency of the edge part.We improve the rendering texture stage and post-processing stage by combining the guided filtering technology,and give the concrete algorithm flow.At the same time,the advantages and disadvantages of traditional SSAO,TSSAO and SSAO combined with guided filtering are compared and analyzed.From the results,the new method can maintain the rendering effect while improving the rendering efficiency..