TzuMao Litzli@ucsd.edu

I am an assistant professor at the CSE department of UCSD, working with awesome people at the Center for Visual Computing. I explore the connections between visual computing algorithms and modern datadriven methods and develop programming languages and systems for facilitating the exploration. I did a 2year postdoc with Jonathan RaganKelley at both MIT CSAIL and UC Berkeley. I did my Ph.D. in the computer graphics group at MIT CSAIL, advised by Frédo Durand. I received my B.S. and M.S. degrees in computer science and information engineering from National Taiwan University in 2011 and 2013, respectively, where I worked with YungYu Chuang at the Communication and Multimedia Lab.
Enhancing Value Function Estimation through FirstOrder StateAction Dynamics in Offline Reinforcement Learning
YunHsuan Lien, PingChun Hsieh, TzuMao Li, YuShuen Wang International Conference on Machine Learning 2024 combining discrete and continuous time RL to expliot firstorder information for fitting value functions in offline RL 

RealTime Path Guiding using Bounding Voxel Sampling
Haolin Lu, Wesley Chang, Trevor Hedstrom, TzuMao Li ACM Transactions on Graphics (Proceedings of SIGGRAPH 2024) a spatial data structure and sampling method for path guiding to efficiently reuse samples across pixels 

Temporally Stable Metropolis Light Transport Denoising using Recurrent Transformer Blocks
Chuhao Chen, Yuze He, TzuMao Li ACM Transactions on Graphics (Proceedings of SIGGRAPH 2024) recurrent transformer blocks are more effective than pixel blending for denoising MLT rendering 

Neural Geometry Fields for Meshes
Venkataram Sivaram, Ravi Ramamoorthi, TzuMao Li SIGGRAPH 2024 (conference track full paper) representing meshes using patches and coordinate neural networks 

Residual Path Integrals for Rerendering
Bing Xu, TzuMao Li, Iliyan Georgiev, Trevor Hedstrom, Ravi Ramamoorthi Computer Graphics Forum (Proceedings of Eurographics Symposium on Rendering 2024) path space importance sampling strategies for rendering the difference between two frames 

Distributions for Compositionally Differentiating Parametric Discontinuities
Jesse Michel, Kevin Mu, Xuanda Yang, Sai Preveen Bangaru, Elias Rojas Collins, Gilbert Bernstein, Jonathan RaganKelley, Michael Carbin, TzuMao Li Proceedings of the ACM on Programming Languages (OOPSLA 2024) a distribution theory formalism for differentiating parametric discontinuities in programs, and support of firstorder functions with separate compilation 

Importance Sampling BRDF Derivatives
Yash Belhe, Bing Xu, Sai Praveen Bangaru, Ravi Ramamoorthi, TzuMao Li ACM Transactions on Graphics (will be presented at SIGGRAPH 2024) importance sampling realvalued functions by decomposing an integral into singlesigned ones with overlapping supports 

Differentiable Visual Computing for Inverse Problems and Machine Learning
Andrew Spielberg, Fangcheng Zhong, Konstantinos Rematas, Krishna Murthy Jatavallabhula, Cengiz Oztireli, TzuMao Li, Derek Nowrouzezahrai Nature Machine Intelligence (2023) a survey article of differentiable graphics algorithms and their applications in machine learning 

Inferring the Future by Imagining the Past
Kartik Chandra*, Tony Chen*, TzuMao Li, Jonathan RaganKelley, Josh Tenenbaum *equal contribution Neural Information Processing Systems 2023 (Spotlight) using a bidirectional path tracing like algorithm to infer the goal of an agent from its current state 

DiscontinuityAware 2D Neural Fields
Yash Belhe, Michaél Gharbi, Matthew Fisher, Iliyan Georgiev, Ravi Ramamoorthi, TzuMao Li ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2023) a hybrid meshneuralnetwork 2D representation that preserves discontinuities when zoomed in 

SLANG.D: Fast, Modular and Differentiable Shader Programming
Sai Bangaru, Lifan Wu, TzuMao Li, Jacob Munkberg, Gilbert Bernstein, Jonathan RaganKelley, Frédo Durand, Aaron Lefohn, Yong He ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2023) Slang meets automatic differentiation 

WarpedArea Reparameterization of Differential Path Integrals
Peiyu Xu, Sai Bangaru, TzuMao Li, Shuang Zhao ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2023) Best Paper Award warped area sampling in path space with materialform reparameterization 

FIPT: Factorized Inverse Path Tracing for Efficient and Accurate MaterialLighting Estimation
Liwen Wu*, Rui Zhu*, Mustafa Yaldiz, Yinhao Zhu, Hong Cai, Janarbek Matai, Fatih Porikli, TzuMao Li, Manmohan Chandraker, Ravi Ramamoorthi *equal contribution International Conference on Computer Vision 2023 (oral presentation) irradiance and radiance caching for speeding up and robustifying inverse path tracing, with an emitter estimation heuristic 

Parameterspace ReSTIR for Differentiable and Inverse Rendering
Wesley Chang, Venkataram Sivaram, Derek Nowrouzezahrai, Toshiya Hachisuka, Ravi Ramamoorthi, and TzuMao Li SIGGRAPH 2023 (conference track full paper) making sampling in inverse rendering faster by reusing information in gradientbased optimization 

Acting as Inverse Inverse Planning /
Storytelling as Inverse Inverse Planning
Kartik Chandra, TzuMao Li, Joshua Tenenbaum, Jonathan RaganKelley SIGGRAPH 2023 (conference track full paper) / Proceedings of the 45th Annual Conference of the Cognitive Science Society (CogSci 2023) (There are two versions of this paper. The first paper is written for graphics audience, and the second one is written for cognitive science audience.)
automatically synthesizing stories as animation sequences by optimizing Theory of Mind models


Physical Cyclic Animations
Shiyang Jia, Stephanie Wang, TzuMao Li, Albert Chern Proceedings of the ACM on Computer Graphics and Interactive Techniques (SCA 2023) simulating physics in a periodic time domain 

Neural FreeViewpoint Relighting for Glossy Indirect Illumination
Nithin Raghavan*, Yan Xiao*, KaiEn Lin, Tiancheng Sun, Sai Bi, Zexiang Xu, TzuMao Li, Ravi Ramamoorthi *equal contribution Computer Graphics Forum (Proceedings of Eurographics Symposium on Rendering 2023) hybrid neural wavelet precomputed radiance transfer 

Differentiable Visual Computing: Challenges and Opportunities
TzuMao Li IEEE Computer Graphics and Applications: Dissertation Impact, 2022 summary of the visions of my PhD thesis. 

Differentiable Rendering of Neural SDFs through Reparameterization
Sai Praveen Bangaru, Michaél Gharbi, TzuMao Li, Fujun Luan, Kalyan Sunkavalli, Miloš Hašan, Sai Bi, Zexiang Xu, Gilbert Bernstein, Frédo Durand SIGGRAPH Asia 2022 (conference track full paper) unbiased differentiable SDF rendering. concurrent with Vicini et al.'s work. some extra memory saving tricks are introduced. 

Designing Perceptual Puzzles by Differentiating Probabilistic Programs
Kartik Chandra, TzuMao Li, Joshua Tenenbaum, Jonathan RaganKelley SIGGRAPH 2022 (conference track full paper) synthesizing optical illusion by differentiating through Bayesian vision models 

Searching for Fast Demosaicking Algorithms
Karima Ma, Michael Gharbi, Andrew Adams, Shoaib Kamil, TzuMao Li, Connelly Barnes, Jonathan RaganKelley ACM Transaction on Graphics (Presented at SIGGRAPH 2022) systematically exploring the Pareto frontier of efficient and highquality datadriven image processing algorithms 

Efficient Automatic Scheduling of Imaging and Vision Pipelines for the GPU
Luke Anderson, Andrew Adams, Karima Ma, TzuMao Li, Tian Jin, Jonathan RaganKelley Proceedings of the ACM on Programming Languages (OOPSLA 2021) a scalable and datadriven Halide autoscheduler that can process large pipelines and output GPU schedules 

Learning to Cluster for Rendering with Many Lights
YuChen Wang, YuTing Wu, TzuMao Li, YungYu Chuang ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2021) adapting both the clustering and sampling distribution in lightcuts rendering using a datadriven method built on reinforcement lightcuts learning 

MultiResolution Shared Representative Filtering for RealTime Depth Completion
YuTing Wu, TzuMao Li, IChao Shen, HongShiang Lin, YungYu Chuang HighPerformance Graphics (HPG) 2021 fast samplingbased cross bilateral filtering for depth completion with large missing regions 

Systematically Differentiating Parametric Discontinuities
Sai Praveen Bangaru*, Jesse Michel*, Kevin Mu, Gilbert Bernstein, TzuMao Li, Jonathan RaganKelley *equal contribution ACM Transactions on Graphics (Proceedings of SIGGRAPH 2021) a programming language perspective on the automatic differention of integrals with discontinuous integrands, and its applications in physics and rendering 

Unbiased WarpedArea Sampling for Differentiable Rendering
Sai Praveen Bangaru, TzuMao Li, Frédo Durand ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2020) solving the differentiable rendering boundary integral with standard area sampling in an unbiased way using divergence theorem 

Differentiable Vector Graphics Rasterization for Editing and Learning
TzuMao Li, Michal Lukáč, Michaël Gharbi, Jonathan RaganKelley ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2020) design choices and applications of differentiable vector graphics rasterization 

PhysicsBased Differentiable Rendering: A Comprehensive Introduction
Shuang Zhao, Wenzel Jakob, TzuMao Li SIGGRAPH 2020 Course our differentiable rendering tutorial! 

DiffTaichi: Differentiable Programming for Physical Simulation
Yuanming Hu, Luke Anderson, TzuMao Li, Qi Sun, Nathan Carr, Jonathan RaganKelley, Frédo Durand International Conference on Learning Representation (ICLR) 2020 automatic differentiated Taichi and applications in modelbased reinforcement learning 

Taichi: A Language for HighPerformance Computation on Spatially Sparse Data Structures
Yuanming Hu, TzuMao Li, Luke Anderson, Jonathan RaganKelley, Frédo Durand ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2019) a dataoriented compiler that decouples hierarchical sparse data structures design from computation 

Learning to Optimize Halide with Tree Search and Random Programs
Andrew Adams, Karima Ma, Luke Anderson, Riyadh Baghdadi, TzuMao Li, Michaël Gharbi, Benoit Steiner, Steven Johnson, Kayvon Fatahalian, Frédo Durand, Jonathan RaganKelley ACM Transactions on Graphics (Proceedings of SIGGRAPH 2019) first Halide autoscheduler that produces faster code comparing to human experts on average 

Samplebased Monte Carlo Denoising using a KernelSplatting Network
Michaël Gharbi, TzuMao Li, Miika Aittala, Jaakko Lehtinen, Frédo Durand ACM Transactions on Graphics (Proceedings of SIGGRAPH 2019). permutation invariant mapping from Monte Carlo samples to an image through splatting 

Differentiable Visual Computing [slides (Keynote)] [slides (Powerpoint)]
TzuMao Li MIT PhD Dissertation ACM SIGGRAPH 2020 Outstanding Doctoral Dissertation Award (announcement) a coherent view of my PhD research, with some new discussions regarding previous work, and some background reviews 

Inverse Path Tracing for Joint Material and Lighting Estimation
Dejan Azinović, TzuMao Li, Anton Kaplanyan, Matthias Nießner Conference on Computer Vision and Pattern Recognition (CVPR), 2019 (oral presentation) applying differentiable rendering for material and lighting reconstruction 

Differentiable Monte Carlo Ray Tracing through Edge Sampling
TzuMao Li, Miika Aittala, Frédo Durand, Jaakko Lehtinen ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2018) computing gradients of the light transport equation through an explicit sampling of Dirac delta functions on triangle edges 

Differentiable Programming for Image Processing and Deep Learning in Halide
TzuMao Li, Michaël Gharbi, Andrew Adams, Frédo Durand, Jonathan RaganKelley ACM Transactions on Graphics (Proceedings of SIGGRAPH 2018) Halide meets automatic differentiation, and a new way to think about datadriven image processing 

Aether: An Embedded Domain Specific Sampling Language for Monte Carlo Rendering
Luke Anderson, TzuMao Li, Jaakko Lehtinen, Frédo Durand ACM Transactions on Graphics (Proceedings of SIGGRAPH 2017) a programming language for Monte Carlo rendering that automatically computes the probability density of a light path sample 

Anisotropic Gaussian Mutations for Metropolis Light Transport through HessianHamiltonian Dynamics
TzuMao Li, Jaakko Lehtinen, Ravi Ramamoorthi, Wenzel Jakob, Frédo Durand ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2015) a Metropolis light transport algorithm that makes use of automatically differentiated Hessian matrix of light path contribution 

DualMatrix Sampling for Scalable Translucent Material Rendering
YuTing Wu, TzuMao Li, YuHsun Lin, and YungYu Chuang IEEE Transactions on Visualization and Computer Graphics (TVCG), 2015 subsurface scattering with manylights using matrix sampling 

SUREbased Optimization for Adaptive Sampling and Reconstruction
TzuMao Li, YuTing Wu, YungYu Chuang ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2012) Stein's unbiased risk estimator for sampling and denoising in Monte Carlo rendering 
lajolla
An educational renderer for UCSD CSE 272 

Deriving Radiative Backpropagation using the Recursive Form of Path Tracing
A short note about the paper "Radiative Backpropagation: An Adjoint Method for LightningFast Differentiable Rendering". I show that you can derive a similar algorithm using traditional automatic differentiation. 

diffvg
A differentiable vector graphics rasterizer with PyTorch and Tensorflow interfaces. 

redner
A differentiable Monte Carlo ray tracer with PyTorch and Tensorflow interfaces. 

Graphics bibtex
A mega bibtex file containing many graphicsrelated literatures. 

Joint Stein’s Unbiased Risk Estimation for Adaptive Sampling and Reconstruction
A short note on a generalized formulation of our SUREbased rendering method. 

dpt
My prototypical renderer. 

smallgdpt
GradientDomain Path Tracing in ~450 lines. 