真实感眩光效果实时绘制

摘要

针对现有眩光效果绘制方法的真实感和速度问题,提出一种基于GPU的真实感眩光效果绘制方法.首先根据光圈和镜头生成带有随机镜头噪声的二维衍射光栅图像；其次考虑夫琅禾费和菲涅耳2种不同的衍射效果,利用预存算法系数的快速傅里叶变换模拟衍射效果的光学过程,并通过衍射效果的光谱模型实现真实感绘制,同时利用2个独立的一维高斯卷积核加速实现bloom效果；再通过随机小角度旋转和混合操作进行真实感增强；最后采用实时光线跟踪渲染框架,在三维场景中实现了真实感眩光效果的实时绘制.该方法的主要步骤采用CUDA实现,充分利用了GPU强大的并行计算能力并兼顾考虑存储器优化策略.实验结果表明,文中方法绘制结果具有较强的真实感和实时性.%To address the problems of current realistic glare rendering approaches,this paper presents a GPU based real-time method for rendering realistic glare.Firstly,the diffraction grating with random lens noise is efficiently generated according to lens aperture.Secondly,based on diffraction principle,a fast Fourier transformation algorithm with pre-computed coefficients is employed to simulate both Fraunhofer and Fresnel diffraction,and a spectrum model is used to achieve photorealistic rendering and two independent one-dimension Gaussian kernels are introduced to achieve bloom effect.Thirdly,we apply random small rotation operations and blend operations to enhance the photorealism.Finally,the glare effect can be added into a three-dimensional scene with the new glare rendering approach integrated into a real-time ray tracing framework.Our method is implemented on CUDA architecture and efficiently utilizes the powerful GPU parallel processing capability and memory hierarchy.Experimental results show that our method can achieve real-time performance and improve realism of scenes.