Wavelet-Based Order-Independent Transparency

Real-time rendering of transparent objects is one of the universal requirements in application fields such as games,virtual reality,and scientific visualization.It is also an important and challenging subject in the field of computer graphics research.In order to achieve realistic rendering effects while meeting the performance requirements of real-time rendering,researchers usually render transparency objects using order-independent transparency algorithm.This paper takes the order-independent transpareny algorithm as the research topic,analyzes the problems of the existing algorithms,and proposes a wavelet based order-independent transparency algorithm.The basic idea of the algorithm in this paper is to use wavelet series to approximate the transmittance function of transparent fragments,so as to avoid the huge computational and memory overhead caused by accurate calculation of transmittance.Specifically,the main work and innovations of this paper include:1.First,this paper proposes a method that uses the wavelet series to approximate the transmittance function.This paper uses the scaling function of db2 wavelet to approximate the transmittance function of the transparent fragments,which can achieve the approximate calculation of the transmittance with higher efficiency and lower approximation error,and solves the problem of excessive calculation and memory overhead required for accurate calculation of transmittance.2.Secondly,an improved transmittance reconstruction method is proposed.In this paper,the transmittance function is indirectly reconstructed by projecting and reconstructing the optical depth function of the transparent fragments.Compared with the transmittance reconstruction method in the Fourier based order-independent transparency algorithm,the algorithm proposed by this paper greatly improves the efficiency of the transmittance reconstruction process.3.Finally,this paper analyzes the problem of unstable rendering results,and proposes a solution that combines depth remapping and temporal filtering,which improves the quality of the final rendering results with only a small amount of additional overhead.Experimental results show that the algorithm proposed by this paper can approximate the exact order-independent transparency algorithm with higher efficiency and lower error;at the same time,compared to the Fourier based order-independent transparency algorithm,the algorithm proposed by this paper can greatly improve the efficiency of the transmittance reconstruction process,thereby improving the overall efficiency of the rendering algorithm.