基于物理的可微渲染综述  

Physically based differentiable rendering:a survey

作　　者：邢健开 徐昆 Xing Jiankai;Xu Kun(Key Laboratory of Pervasive Computing,Ministry of Education,Beijing 100084,China;Beijing National Research Center for Information Science and Technology,Beijing 100084,China;Department of Computer Science and Technology,Tsinghua University,Beijing 100084,China)

机构地区：[1]普适计算教育部重点实验室,北京100084 [2]北京信息科学与技术国家研究中心,北京100084 [3]清华大学计算机系,北京100084

出　　处：《中国图象图形学报》2024年第10期2912-2925,共14页Journal of Image and Graphics

基　　金：国家自然科学基金项目(62372257)。

摘　　要：可微渲染技术是当前计算机图形学与计算机视觉方向的研究热点,其目标是将计算机图形学中的渲染流水线进行可微化改造以支持计算渲染的输出图像关于输入参数如几何、材质等参数的梯度。结合渲染图像与目标图像之间的损失函数,可微渲染允许在生成式分析的框架中,通过梯度下降的方式从图像中推理出场景参数,是解决三维重建、逆向渲染等领域问题的有效方法,并在虚拟现实、自动驾驶等领域有着广泛的应用前景。基于物理的可微渲染旨在对基于物理的渲染管线进行可微化改造,主要涉及对场景几何和材质的表达,以及光路传输模拟过程的梯度计算方法。本文对近年来基于物理的可微渲染领域的发展情况进行了调研,总结了基于物理的可微渲染研究进展。首先总体介绍正向渲染和可微渲染的计算方法;然后介绍如何针对具体的几何、材质以及相机的表达方式进行梯度计算;讨论如何提高可微渲染的效率和鲁棒性;展示可微渲染如何应用于实际任务中;最后本文展望了可微渲染的发展趋势,期望推动该领域的进一步发展。scene description as input and typically generates a 2D image as output.The theory and practice of rendering have remarkably advanced through years of research.In recent years,inverse rendering has emerged as a new research focus in the field of computer graphics due to the development of digital technology.The objective of inverse rendering is to reverse the rendering process and deduce scene parameters from the output image,which is equivalent to solving the inverse function of the rendering function.This process plays a crucial role in addressing perception problems in diverse advanced technological domains,including virtual reality,autonomous driving,and robotics.Numerous methods exist for implementing inverse rendering,with the current mainstream framework being optimization through“analysis by synthesis”.First,it estimates a set of initial scene parameters,then performs forward rendering on the scene,compares the rendered result with the target image,and then minimizes the difference(loss function)by opti mizing the scene parameters using gradient descent-based method.This pipeline necessitates the ability to compute the derivatives of the output image in forward rendering with respect to the input parameters.Consequently,differentiable rendering has emerged to fulfill this requirement.Specifically,the research topic of differentiable rendering is to convert the forward rendering pipeline in computer graphics into a differentiable form,enabling the differentiation of the output image with respect to input parameters such as geometry,material,light source,and camera.Currently,forward rendering can be broadly categorized into three types:rasterization-based rendering,physically based rendering,and the emerging neural rendering.Rasterization-based rendering is a fundamental technique in computer graphics that converts geometric shapes into pixels for display.It involves projecting 3D objects onto a 2D screen,performing hidden surface removal,shading,and texturing to create realistic images efficiently.Whil

关 键 词：渲染 可微渲染 逆向渲染 光线跟踪 三维重建 

分 类 号：TP37[自动化与计算机技术—计算机系统结构]