Toshiya Hachisuka
(Google Scholar)
Associate Professor David R. Cheriton School of Computer Science, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1 (affiliated with Computer Graphics Lab, Computational Mathematics, and Scientific Computation Group) toshiya.hachisuka@uwaterloo.ca Pronunciation of my name: "Hachisuka" has silent "u" (e.g., "Ha-chee-ska"). "Toshiya" has stress on "To" (e.g., "Toe-she-ya", *not* like "Toshiba", but like "Joshua"). I will be away on sabbatical during January 2024 to June 2024 and my email response might be delayed during this period. I am currently not looking for a new student. However, if you are a current student at UWaterloo and would like to work with me, feel free to reach out to me. By default, I will decline to write a recommendation letter if you just took one of my courses and never worked with me outside of it. If you are interested in working with me as a new student later than 2025 or so, please first read this (say that you read it in your email) and contact me by stating your interest in rendering or relevant subjects within computer graphics. In case you apply for a graduate study, please also send me a one-page summary of your understanding of one of our papers. I might not reply to your email if you failed to follow any of the above. In particular, I may delete your email immediately if it is apparent that you are not really interested in working with me on the topics that I work on within computer graphics. Applications without any contact in advance may not be given full consideration. |
NOTES AND TECHNICAL REPORTS
"Quantum Ray Marching for Reformulating Light Transport Simulation" [supplemental]
L. Mosier, M. McGuire, and T. Hachisuka
ACM SIGGRAPH Asia 2023 (Conference Track), 2023
(First scalable light transport algorithm on quantum computers.)
"Input-Dependent Uncorrelated Weighting for Monte Carlo Denoising" [supplemental] [project]
J. Back, B. Hua, T. Hachisuka, and B. Moon
ACM SIGGRAPH Asia 2023 (Conference Track), 2023
(Intrinsically low-bias denoising for Monte Carlo rendering.)
"A Practical Walk-on-Boundary Method for Boundary Value Problems" [project]
R. Sugimoto, T. Chen, Y. Jiang, C. Batty, and T. Hachisuka
ACM Transactions on Graphics (SIGGRAPH North America 2023), 2023
(Versatile Monte Carlo ray tracing solver for boundary value problems.)
"Parameter-space ReSTIR for Differentiable and Inverse Rendering" [project]
W. Chang, V. Sivaram, D. Nowrouzezahrai, T. Hachisuka, R. Ramamoorthi, and T. Li
ACM SIGGRAPH North America 2023 (Conference Track), 2023
(Resampled path reuse for differentiable rendering.)
"A Monte Carlo Method for Fluid Simulation" [project]
D. Rioux-Lavoie*, R. Sugimoto* (* joint first authors), T. Özdemir, N. H. Shimada, C. Batty, D. Nowrouzezahrai, and T. Hachisuka
ACM Transactions on Graphics (SIGGRAPH Asia 2022), 2022
(Monte Carlo framework for solving Navier-Stokes equations.)
"Marginal Multiple Importance Sampling" [supplemental]
R. West, I. Georgiev, and T. Hachisuka
ACM SIGGRAPH Asia 2022 (Conference Track), 2022
(Unbiased approximation of MIS when one or more of the sampling techniques has an intractable marginal PDF.)
"Surface-Only Dynamic Deformables using a Boundary Element Method" [project]
R. Sugimoto, C. Batty, and T. Hachisuka
ACM SIGGRAPH/Eurographics Symposium on Computer Animation 2022 (received "Best Paper Award"), 2022
(A practical extension of BEM for surface-only deformables.)
"Single-pass Stratified Importance Resampling" [project]
E. Ciklabakkal, A. Gruson, I. Georgiev, D. Nowrouzezahrai, and T. Hachisuka
Eurographics Symposium on Rendering 2022 (CGF track), 2022
(Stratification made available within resampled importance sampling.)
"Lightweight Multidimensional Adaptive Sampling for GPU Ray Tracing"
D. Meister and T. Hachisuka
Journal of Computer Graphics Techniques, 2022
(GPU-friendly MDAS.)
"Regression-based Monte Carlo Integration" [project]
C. Salaun, A. Gruson, B. Hua, T. Hachisuka, and G. Singh
ACM Transactions on Graphics (SIGGRAPH North America 2022), 2022
(Connecting regression and MC integration to have a drop-in improvement of MC integration.)
"Self-Supervised Post-Correction for Monte Carlo Denoising" [project]
J. Back, B. Hua, T. Hachisuka, and B. Moon
ACM SIGGRAPH North America 2022 (Conference Track), 2022
(Improving MC denoising just based on run-time rendered images.)
"Fast Polygonal Splatting using Directional Kernel Difference" [talk]
Y. Moroto, T. Hachisuka, N. Umetani
Eurographics Symposium on Rendering 2021 (DL-only track), 2021
(Efficient blur with polygonal kernels using directional differences.)
"Deep Combiner for Independent and Correlated Pixel Estimates" [project]
J. Back, B. Hua, T, Hachisuka, and B. Moon
ACM Transactions on Graphics (SIGGRAPH Asia 2020), 2020
(Effective combination of independent and correlated sampling via deep learning.)
"Continuous Multiple Importance Sampling" [project]
R. West, I. Georgiev, A. Gruson, and T. Hachisuka
ACM Transactions on Graphics (SIGGRAPH North America 2020), 2020
(Continuous generalization of multiple importance sampling.)
"A Model for Soap Film Dynamics with Evolving Thickness" [project]
S. Ishida*, P. Synak* (* joint first authors), F. Narita, T. Hachisuka, and C. Wojtan
ACM Transactions on Graphics (SIGGRAPH North America 2020), 2020
(Bubble dynamics simulation with evolving thickness.)
"Quantum Coin Method for Numerical Integration" [slides] [code]
N. H. Shimada and T. Hachisuka
Computer Graphics Forum, 2020
(Practical numerical integration with quantum computing.)
"Delayed Rejection Metropolis Light Transport" [project]
D. Rioux-Lavoie*, J. Litalien* (* joint first authors), A. Gruson, T. Hachisuka, and D. Nowrouzezahrai
ACM Transactions on Graphics (Volume 39, Issue 3, presented at SIGGRAPH North America 2020), 2020
(Delayed rejection in MCMC applied to rendering.)
"Stratified Markov Chain Monte Carlo Light Transport" [comparisons]
A. Gruson, R. West, and T. Hachisuka
Eurographics 2020, 2020
(Perfect image-space stratification with MCMC.)
"Deep Adaptive Wavelet Network"
M. X. B. Rodriguez, A. Gruson, L. F. Polania, S. Fujieda, F. P. Ortiz, K. Takayama, and T. Hachisuka
IEEE Winter Conference on Applications of Computer Vision (WACV) 2020, 2020
(Trainable wavelets within convolutional neural networks.)
"Integral Formulations of Volumetric Transmittance" [slides]
I. Georgiev*, Z. Misso* (*joint first authors), T. Hachisuka, D. Nowrouzezahrai, J. Křivánek, and W. Jarosz
ACM Transactions on Graphics (SIGGRAPH Asia 2019), 2019
(Integral formulations of transmittance that are suitable for unbiased Monte Carlo integration.)
"Scalable Virtual Ray Lights Rendering for Participating Media " [slides]
N. Vibert, A. Gruson, H. Stokholm, T. Mortensen, W. Jarosz, T. Hachisuka, and D. Nowrouzezahrai
Eurographics Symposium on Rendering 2019 (CGF track), 2019
(Lightcuts-like algorithm for VRLs with a proper error bound.)
"A Frequency Analysis and Dual Hierarchy for Efficient Rendering of Subsurface Scattering" [slides]
D. Milaenen, L. Belcour, J. P. Guertin, T. Hachisuka, and D. Nowrouzezahrai
Graphics Interface 2019 (received "Best Student Paper Award"), 2019
(Accelerating rendering of translucent objects via dual-tree traversal)
"A Survey on Gradient-Domain Rendering"
B. Hua, A. Gruson, V. Petitjean, M. Zwicker, D. Nowrouzezahrai, E. Eisemann, and T. Hachisuka
Eurographics 2019 STARs, 2019
(Survey on gradient-domain rendering)
"Light Transport Simulation in the Gradient Domain"
B. Hua, A. Gruson, M. Zwicker, and T. Hachisuka
SIGGRAPH Asia 2018 Courses, 2018
(Course on gradient-domain rendering)
"Geometry-Aware Metropolis Light Transport" [project]
H. Otsu, J. Hanika, T. Hachisuka, and C. Dachsbacher
ACM Transactions on Graphics (SIGGRAPH Asia 2018), 2018
(MCMC rendering which efficiently takes the visibility term into accout)
"Matrix Bidirectional Path Tracing"
C. R. A. Chaitanya, L. Belcour, T. Hachisuka, S. Premože, J. Pantaleoni, and D. Nowrouzezahrai
Eurographics Symposium on Rendering 2018 (EI & I track), 2018
(Matrix reformulation and stratified subsampling of light subpaths in bidirectional path tracing)
"Gradient-Domain Volumetric Photon Density Estimation" [project]
A. Gruson, B. Hua, N. Vibert, D. Nowrouzezahrai, and T. Hachisuka
ACM Transactions on Graphics (SIGGRAPH North America 2018), 2018
(Gradient-domain formulation of volumetric photon density estimation including beams and planes)
"Efficient Energy-Compensated VPLs using Photon Splatting" [project]
J. Sriwasansak, A. Gruson, and T. Hachisuka
ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (long papers) 2018, 2018
(More accurate VPL rendering using photon splatting)
"Reproducing Spectral Reflectances from Tristimulus Colors" [project]
H. Otsu, M. Yamamoto, and T. Hachisuka
Computer Graphics Forum, 2018
(Data-driven approach for converting RGB to spectrum)
"Thinking Outside the Cornell Box: Non-rendering Research by a Rendering Guy"
T. Hachisuka
Invited talk, MEIS 2017, 2017
(My recent attempts on non-rendering research)
"A Hyperbolic Geometric Flow for Evolving Films and Foams" [project]
S. Ishida, M. Yamamoto, R. Ando, and T. Hachisuka
ACM Transactions on Graphics (SIGGRAPH Asia 2017), 2017
(Geometric reformulation of physically based film animation)
"Supervised Learning of How to Blend Light Transport Simulations"
H. Otsu, S. Kinuwaki, and T. Hachisuka
The Proceedings of the MCQMC 2016, 2017
(General framework for automatically blending light transport algorithms via machine learning)
"Extended Path Integral Formulation for Volumetric Transport" [slides]
T. Hachisuka, I. Georgiev, W. Jarosz, J. Křivánek, and D. Nowrouzezahrai
Eurographics Symposium on Rendering 2017 (EI & I track), 2017
(Alternative formulation that unifies path integration and photon density estimation including beams)
"Fusing State Spaces for Markov Chain Monte Carlo Rendering" [project]
H. Otsu, A. S. Kaplanyan, J. Hanika, C. Dachsbacher, and T. Hachisuka
ACM Transactions on Graphics (SIGGRAPH North America 2017), 2017
(How to use PSS-style MLT and Veach-style MLT simultaneously)
"Parameter Estimation of BSSRDF for Heterogeneous Materials" [slides]
H. Sone, T. Hachisuka, and T. Koike
Eurographics 2017 Short Papers, 2017
(Technique to use homogeneous BSSRDF models for rendering heterogeneous media)
"Gradient-Domain Photon Density Estimation" [project]
B. Hua, A. Gruson, D. Nowrouzezahrai, and T. Hachisuka
Computer Graphics Forum (Eurographics 2017), 2017
(Gradient-domain formulation of photon density estimation)
"Secrets of Parthenon Renderer"
T. Hachisuka
Invited seminar, Tokyo Demo Fest, 2017
(Technical bits behind one of the first, publicly available, GPGPU offline rendering systems)
"Robust Light Transport Simulation via Metropolized Bidirectional Estimators"
M. Šik, H. Otsu, T. Hachisuka, and J. Křivánek
ACM Transactions on Graphics (SIGGRAPH Asia 2016), 2016
(VCM/UPS with Markov chain Monte Carlo)
"Rise of the Machines in Monte Carlo Integration for Rendering"
T. Hachisuka
Talk in the special session: Graphics and Transport, MCQMC2016, 2016
(On-going work on deep learning in Monte Carlo integration)
"Implementing a Practical Rendering System using GLSL" [code] [arXiv]
T. Hachisuka
Invited seminar, Tokyo Demo Fest, 2015
(Various topics on how to implement SPPM and BVH using only GLSL)
"Directional Dipole Model for Subsurface Scattering" [slides] [code] [demo]
J. R. Frisvad, T. Hachisuka, and T. K. Kjeldsen
ACM Transactions on Graphics (Volume 34 Issue 1, presented at SIGGRAPH North America 2015), 2014
(Fully analytical BSSRDF that takes directions of light into account)
"Multiplexed Metropolis Light Transport" [slides] [code - mmlt] [code - pssmlt]
T. Hachisuka, A. S. Kaplanyan, and C. Dachsbacher
ACM Transactions on Graphics (SIGGRAPH North America 2014), 2014
(Fusion of Markov chain Monte Carlo and multiple importance sampling)
"Unifying Points, Beams, and Paths in Volumetric Light Transport Simulation" [slides] [poster] [code] [comparison] [supplemental]
J. Křivánek, I. Georgiev, T. Hachisuka, P. Vévoda, M. Šik, D. Nowrouzezahrai, and W. Jarosz
ACM Transactions on Graphics (SIGGRAPH North America 2014), 2014
(Unified formulation of Monte Carlo path integration and photon density estimation with points and beams)
"At the Boundary between Light Transport Simulation and Computational Statistics"
T. Hachisuka
Talk in the special session: Advanced light transport simulation, MCQMC2014, 2014
(Overview of connections between some of my work in rendering and more general problems in computational statistics)
"State of the Art in Photon-Density Estimation"
T. Hachisuka and W. Jarosz (organizers) (check out the course website for the full list of speakers.)
SIGGRAPH Asia 2013 Courses, 2013
(Course on recent advancements in photon density estimation)
"Joint Importance Sampling of Low-Order Volumetric Scattering" [comparison] [slides]
I. Georgiev, J. Křivánek, T. Hachisuka, D. Nowrouzezahrai, and W. Jarosz
ACM Transactions on Graphics (SIGGRAPH Asia 2013), 2013
(Importance sampling of multiple geometry terms and phase functions in participating media)
"Robust Image Denoising using a Virtual Flash Image for Monte Carlo Ray Tracing"
B. Moon, J. Jun, J. Lee, K. Kim, T. Hachisuka, and S. Yoon
Computer Graphics Forum (Volume 32 Number 1, presented at EGSR 2014), 2012
(Denoising method with a new image feature)
"A Path Space Extension for Robust Light Transport Simulation" [supplemental] [slides] [code (refer to SmallVCM. UPS = VCM in implementation.) ]
T. Hachisuka, J. Pantaleoni, and H. W. Jensen
ACM Transactions on Graphics (SIGGRAPH Asia 2012), 2012
(Extended path integral formulation for Monte Carlo path integration and photon density estimation)
"Randomized Coherent Sampling for Reducing the Perceptual Error of Rendered Images" [poster]
L. Staal and T. Hachisuka
SIGGRAPH North America 2012 Posters, 2012
(New uniform sampling method that reduces perceptual noise in Monte Carlo ray tracing)
"State of the Art in Photon-Density Estimation"
T. Hachisuka and W. Jarosz (organizers) (check out the course website for the full list of speakers.)
SIGGRAPH North America 2012 Courses, 2012
(Course on recent advancements in photon density estimation)
"Robust Adaptive Photon Tracing using Photon Path Visibility" [slides]
T. Hachisuka and H. W. Jensen
ACM Transactions on Graphics (Volume 30 Issue 5, presented at SIGGRAPH North America 2013), 2011
(Adaptive Markov chain Monte Carlo sampling for photon tracing with a simple target distribution)
"A Progressive Error Estimation Framework for Photon Density Estimation"
T. Hachisuka, W. Jarosz, and H. W. Jensen
ACM Transactions on Graphics (SIGGRAPH Asia 2010), 2010
(Full paper of the talk at SIGGRAPH 2010)
"Parallel Progressive Photon Mapping on GPUs" [code] [slides]
T. Hachisuka and H. W. Jensen
SIGGRAPH Asia 2010 Technical Sketches, 2010
(Simple and parallel range-query algorithm with randomization)
"An Error Estimation Framework for Photon Density Estimation" [slides]
T. Hachisuka, W. Jarosz, and H. W. Jensen
SIGGRAPH North America 2010 Talks: Rendering Intangibles, 2010
(Error estimation for progressive photon density estimation)
"Stochastic Progressive Photon Mapping" [slides] [code] [data0] [data1]
T. Hachisuka and H. W. Jensen
ACM Transactions on Graphics (SIGGRAPH Asia 2009), 2009
(First progressive average density estimator for distribution effects)
"An Empirical BSSRDF Model"
C. Donner, J. Lawrence, R. Ramamoorthi, T. Hachisuka, H. W. Jensen, and S. Nayar
ACM Transactions on Graphics (SIGGRAPH North America 2009), 2009
(Precomputed BSSRDFs for moderately scattering media)
"Progressive Photon Mapping" [slides] [code] [code with comments] [data0] [data1]
T. Hachisuka, S. Ogaki, and H. W. Jensen
ACM Transactions on Graphics (SIGGRAPH Asia 2008), 2008
(New progressive density estimator for light transport simulation)
"Multidimensional Adaptive Sampling and Reconstruction for Ray Tracing" [slides] [code] [data0] [data1]
T. Hachisuka, W. Jarosz, R. P. Weistroffer, K. Dale, G. Humphreys, M. Zwicker, and H. W. Jensen
ACM Transactions on Graphics (SIGGRAPH North America 2008), 2008
(Adaptive sampling and reconstruction in the random number space)
"Combined Lagrangian-Eulerian Approach for Accurate Advection" [poster] [code]
T. Hachisuka
SIGGRAPH North America 2005 Posters (2nd Place in SRC:Undergraduate division at SIGGRAPH), 2005
(Advection equation solver using mapping functions)
"High-Quality Global Illumination Rendering Using Rasterization"
T. Hachisuka
GPU Gems 2: Programming Techniques for High Performance Graphics and General-Purpose Computation (Chapter 38), 2005
(Application of the poster at SIGGRAPH 2004)
"Final Gathering on GPU" [poster]
T. Hachisuka
GP2, ACM Workshop on General Purpose Computing on Graphics Processors (also presented at SIGGRAPH North America 2004 Posters), 2004
(Rasterization-based final gathering)
DISSERTATION AND THESIS
"Deep Adaptive Wavelet Network"
M. X. B. Rodriguez, A. Gruson, L. F. Polania, S. Fujieda, F. P. Ortiz, K. Takayama, and T. Hachisuka
Manuscript, Dec 2019
(Trainable wavelets within convolutional neural networks.)
"Quantum Coin Method for Numerical Integration"
N. H. Shimada and T. Hachisuka
Manuscript, Oct 2019
(Practical numerical integration with quantum computing.)
"Wavelet Convolutional Neural Networks for Texture Classification" [updated manuscript]
S. Fujieda, K. Takayama, and T. Hachisuka
Manuscript, July 2017
(Wavelets within convolutional neural networks.)
"Five Common Misconceptions about Bias in Light Transport Simulation"
T. Hachisuka
Manuscript, November 2013
(Notes on five common misconceptions about bias in rendering.)
"Directional Dipole for Subsurface Scattering in Translucent Materials" [slides]
J. R. Frisvad, T. Hachisuka, and T. K. Kjeldsen
Manuscript, August 2013
(Analytical BSSRDF that takes directions of light into account.)
"A Path Space Extension for Robust Light Transport Simulation"
T. Hachisuka, J. Pantaleoni, and H. W. Jensen
NVIDIA Technical Report NVR-2012-001, April 2012
(Unified sampling framework for Monte Carlo path integration and photon density estimation.)
"Ray Tracing on Graphics Hardware"
T. Hachisuka
Research Exam, University of California at San Diego, 2009
(Comparative studies of GPU ray tracing algorithms.)
"Generalized Polarization Ray Tracing using a Monte-Carlo Method"
T. Hachisuka
Final project in CSE 272, University of California at San Diego, 2007
(Monte Carlo formulation of polarization effects.)
EDUCATION
"Robust Light Transport Simulation using Progressive Density Estimation"
T. Hachisuka (Advisor: Prof. Henrik Wann Jensen)
Dissertation for Doctor of Philosophy, University of California at San Diego, 2011
(Light transport simulation framework based on progressive density estimation. )
"Advection Equation Solver using Mapping Functions"
T. Hachisuka (Advisor: Prof. Seiichi Koshizuka)
Thesis for Bachelor of Engineering, University of Tokyo, 2006
(Formulation of the advection equation as mapping.)