Publications

A Free-Space Diffraction BSDF

ACM Transactions on Graphics (SIGGRAPH), 2024

Free-space diffractions are an optical phenomenon where light appears to “bend” around the geometric edges and corners of scene objects. In this paper we present an efficient method to simulate such effects. We derive an edge-based …
doi PDF Pdf-lowres Supplementary Github Video
A Free-Space Diffraction BSDF

Area ReSTIR: Resampling for Real-Time Defocus and Antialiasing

ACM Transactions on Graphics (SIGGRAPH), 2024

Recent advancements in spatiotemporal reservoir resampling (ReSTIR) leverage sample reuse from neighbors to efficiently evaluate the path integral. Like rasterization, ReSTIR methods implicitly assume a pinhole camera and evaluate the light arriving …
doi PDF Brief Summary Video Submission Video Image Viewer
Area ReSTIR: Resampling for Real-Time Defocus and Antialiasing

Real-Time Neural Appearance Models

ACM Transactions on Graphics (ToG), 2024

We present a complete system for real-time rendering of scenes with complex appearance previously reserved for offline use. This is achieved with a combination of algorithmic and system level innovations.Our appearance model utilizes learned …
Project doi PDF
Real-Time Neural Appearance Models

Filtering After Shading with Stochastic Texture Filtering

ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D), 2024
🏆 Best Paper

2D texture maps and 3D voxel arrays are widely used to add rich detail to the surfaces and volumes of rendered scenes, and filtered texture lookups are integral to producing high-quality imagery. We show that applying the texture filter after …
PDF Video Slides Supplementary Shadertoy-1 Shadertoy-2 Talk
Filtering After Shading with Stochastic Texture Filtering

Evaluating and Improving Rendered Visual Experiences

PhD dissertation from Centre for Mathematical Sciences, Lund University, 2024

Rendered imagery is presented to us daily. Special effects in movies, video games, scientific visualizations, and marketing catalogs all often rely on images generated through computer graphics. However, with all the possibilities that rendering …
PDF Project
Evaluating and Improving Rendered Visual Experiences

Estimates of Temporal Edge Detection Filters in Human Vision

ACM Transactions on Applied Perception (TAP), 2024

Edge detection is an important process in human visual processing. However, as far as we know, few attempts have been made to map the temporal edge detection filters in human vision. To that end, we devised a user study and collected data from which …
doi PDF Code Video
Estimates of Temporal Edge Detection Filters in Human Vision

Decorrelating ReSTIR Samplers via MCMC Mutations

ACM Transactions on Graphics (ToG), 2024

Monte Carlo rendering algorithms often utilize correlations between pixels to improve efficiency and enhance image quality. For real-time applications in particular, repeated reservoir resampling offers a powerful framework to reuse samples both …
doi PDF Supplementary
Decorrelating ReSTIR Samplers via MCMC Mutations

SLANG.D: Fast, Modular and Differentiable Shader Programming

ACM Transactions on Graphics (SIGGRAPH Asia), 2023

We introduce SLANG.D, a shading language that incorporates first-class automatic differentiation support derived from the Slang language. The new shading language allows us to transform a Direct3D-based path tracer to be fully differentiable with …
doi PDF Presentation Github
SLANG.D: Fast, Modular and Differentiable Shader Programming

Conditional Resampled Importance Sampling and ReSTIR

SIGGRAPH Asia (Conference Track), 2023

Recent work on generalized resampled importance sampling (GRIS) enables importance-sampled Monte Carlo integration with random variable weights replacing the usual division by probability density. This enables very flexible spatiotemporal sample …
doi PDF Video Supplementary Presentation Prototype
Conditional Resampled Importance Sampling and ReSTIR

ART-Owen Scrambling

ACM Transactions on Graphics (SIGGRAPH Asia), 2023

We present a novel algorithm for implementing Owen-scrambling,combining the generation and distribution of the scrambling bits in a single self-contained compact process. We employ a context-free grammar to build a binary tree of symbols, and equip …
doi PDF
ART-Owen Scrambling

Amortizing Samples in Physics-Based Inverse Rendering using ReSTIR

ACM Transactions on Graphics (SIGGRAPH Asia), 2023

Recently, great progress has been made in physics-based differentiable rendering. Existing differentiable rendering techniques typically focus on static scenes, but during inverse rendering—a key application for differentiable …
doi PDF Supplementary
Amortizing Samples in Physics-Based Inverse Rendering using ReSTIR

MesoGAN: Generative Neural Reflectance Shells

Computer Graphics Forum, 2023

We introduce MesoGAN, a model for generative 3D neural textures. This new graphics primitive represents mesoscale appearance by combining the strengths of generative adversarial networks (StyleGAN) and volumetric neural field rendering. The primitive …
doi PDF Project
MesoGAN: Generative Neural Reflectance Shells

Path tracing in Production: The Path of Water

ACM SIGGRAPH Courses, 2023

doi PDF
Path tracing in Production: The Path of Water

Flexible Isosurface Extraction for Gradient-Based Mesh Optimization

ACM Transactions on Graphics (SIGGRAPH), 2023

This work considers gradient-based mesh optimization, where we iteratively optimize for a 3D surface mesh by representing it as the isosurface of a scalar field, an increasingly common paradigm in applications including photogrammetry, generative …
Project doi PDF
Flexible Isosurface Extraction for Gradient-Based Mesh Optimization

A Gentle Introduction to ReSTIR: Path Reuse in Real-time

ACM SIGGRAPH Courses, 2023

A course gently introducing the basics of Monte Carlo integration, resampling, RIS, ReSTIR, and rendering applications of ReSTIR.
Project doi
A Gentle Introduction to ReSTIR: Path Reuse in Real-time

Recursive Control Variates for Inverse Rendering

ACM Transactions on Graphics (SIGGRAPH), 2023

We present a method for reducing errors—variance and bias—in physically based differentiable rendering (PBDR). Typical applications of PBDR repeatedly render a scene as part of an optimization loop involving gradient descent. The actual …
doi PDF Code Results
Recursive Control Variates for Inverse Rendering

Ray-aligned Occupancy Map Array for Fast Approximate Ray Tracing

Eurographics Symposium on Rendering, 2023

We present a new software ray tracing solution that efficiently computes visibilities in dynamic scenes. We first introduce a novel scene representation: ray-aligned occupancy map array (ROMA) that is generated by rasterizing the dynamic scene once …
doi PDF Video Slides
Ray-aligned Occupancy Map Array for Fast Approximate Ray Tracing

Random-Access Neural Compression of Material Textures

SIGGRAPH (Conference Track), 2023
🏆 Honorable Mention

The continuous advancement of photorealism in rendering is accompanied by a growth in texture data and, consequently, increasing storage and memory demands. To address this issue, we propose a novel neural compression technique specifically designed …
Project doi
Random-Access Neural Compression of Material Textures

Microfacet theory for non-uniform heightfields

SIGGRAPH (Conference Track), 2023

We propose new methods for combining NDFs in microfacet theory, enabling a wider range of surface statistics. The new BSDFs that follow allow for independent adjustment of appearance at grazing angles, and can’t be represented by linear blends …
Project doi PDF
Microfacet theory for non-uniform heightfields

Inverse Global Illumination Using a Neural Radiometric Prior

SIGGRAPH (Conference Track), 2023

Inverse rendering methods that account for global illumination are becoming more popular, but current methods require evaluating and automatically differentiating millions of path integrals by tracing multiple light bounces, which remains expensive …
doi PDF Video
Inverse Global Illumination Using a Neural Radiometric Prior

A Practical and Hierarchical Yarn-based Shading Model for Cloth

Computer Graphics Forum, 2023
🏆 Best Paper

doi PDF
A Practical and Hierarchical Yarn-based Shading Model for Cloth

Neural Fields meet Explicit Geometric Representations for Inverse Rendering of Urban Scenes

IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2023

Reconstruction and intrinsic decomposition of scenes from captured imagery would enable many applications such as relighting and virtual object insertion. Recent NeRF based methods achieve impressive fidelity of 3D reconstruction, but bake the …
Project doi PDF
Neural Fields meet Explicit Geometric Representations for Inverse Rendering of Urban Scenes

Fast Procedural Noise by Monte Carlo Sampling

Eurographics Symposium on Rendering, 2023

Procedural noise functions are widely used in computer graphics as a way to add texture detail to surfaces and volumes. Many noise functions are based on weighted sums that can be expressed in terms of random variables, which makes it possible to …
doi PDF
Fast Procedural Noise by Monte Carlo Sampling

Tight Bounding Boxes for Voxels and Bricks in a Signed Distance Field Ray Tracer

Eurographics (Short Papers), 2023

We present simple methods to compute tight axis-aligned bounding boxes for voxels and for bricks of voxels in a signed distance function renderer based on ray tracing. Our results show total frame time reductions of 20-31% in a real-time path tracer.
Project doi PDF
Tight Bounding Boxes for Voxels and Bricks in a Signed Distance Field Ray Tracer

Luminance-Preserving and Temporally Stable Daltonization

Eurographics (Short Papers), 2023

We propose a novel, real-time algorithm for recoloring images to improve the experience for a color vision deficient observer. The output is temporally stable and preserves luminance, the most important visual cue. It runs in 0.2 ms per frame on a …
doi PDF Supplementary Video Presentation
Luminance-Preserving and Temporally Stable Daltonization

Physically Based Rendering: From Theory to Implementation, 4th Ed.

Book from MIT Press, 2023

Project
Physically Based Rendering: From Theory to Implementation, 4th Ed.

Joint Neural Denoising of Surfaces and Volumes

ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D), 2023
🏆 Best Presentation

We combine state-of-the-art techniques into a system for high-quality, interactive rendering of participating media. We leverage unbiased volume path tracing with multiple scattering, temporally stable neural denoising and NanoVDB, a fast, sparse …
doi PDF Video Supplementary
Joint Neural Denoising of Surfaces and Volumes

Shape, Light, and Material Decomposition from Images using Monte Carlo Rendering and Denoising

Advances in Neural Information Processing Systems (NeurIPS), 2022

Recent advances in differentiable rendering have enabled high-quality reconstruction of 3D scenes from multi-view images. Most methods rely on simple rendering algorithms: pre-filtered direct lighting or learned representations of irradiance. We show …
Project PDF
Shape, Light, and Material Decomposition from Images using Monte Carlo Rendering and Denoising

Lightweight Neural Basis Functions for All-Frequency Shading

SIGGRAPH Asia (Conference Track), 2022

Basis functions provide both the abilities for compact representation and the properties for efficient computation. Therefore, they are pervasively used in rendering to perform all-frequency shading. However, common basis functions, including …
doi PDF Video Supplementary
Lightweight Neural Basis Functions for All-Frequency Shading

Ray Tracing of Signed Distance Function Grids

Journal of Computer Graphics Techniques, 2022

We evaluate the performance of a wide set of combinations of traversal and voxel intersection testing of signed distance function grids in a path tracing setting. In addition, we present an optimized way to compute the intersection between a ray and …
Project PDF
Ray Tracing of Signed Distance Function Grids

The Falcor Rendering Framework

BSD-Licensed Github Repository, 2022

Github

Generalized Resampled Importance Sampling: Foundations of ReSTIR

ACM Transactions on Graphics (SIGGRAPH), 2022

As scenes become ever more complex and real-time applications embrace ray tracing, path sampling algorithms that maximize quality at low sample counts become vital. Recent resampling algorithms building on Talbot et al.’s [2005] resampled importance …
doi PDF Video Presentation Supplementary Code
Generalized Resampled Importance Sampling: Foundations of ReSTIR

Unbiased and consistent rendering using biased estimators

ACM Transactions on Graphics (ToG), 2022

We introduce a general framework for transforming biased estimators into unbiased and consistent estimators for the same quantity. We show how several existing unbiased and consistent estimation strategies in rendering are special cases of this …
doi PDF Project
Unbiased and consistent rendering using biased estimators

Spatiotemporal Blue Noise Masks

Eurographics Symposium on Rendering, 2022

Blue noise error patterns are well suited to human perception, and when applied to stochastic rendering techniques, blue noise masks can minimize unwanted low-frequency noise in the final image. Current methods of applying different blue noise masks …
Project doi PDF
Spatiotemporal Blue Noise Masks

Real-Time Path Tracing and Beyond

Keynote, High Performance Graphics, 2022

Real-time graphics is on the cusp of a historic transition to path tracing. With recent advances in hardware ray tracing, systems research, stochastic light sampling, and denoising, we show that complex light transport effects can be path traced in …
Video Slides
Real-Time Path Tracing and Beyond

Practical Aspects of Spectral Data in Digital Content Production

ACM SIGGRAPH Courses, 2022

Project doi PDF
Practical Aspects of Spectral Data in Digital Content Production

A Position-Free Path Integral for Homogeneous Slabs and Multiple Scattering on Smith Microfacets

Computer Graphics Forum, 2022

We consider the problem of multiple scattering on Smith microfacets. This problem is equivalent to computing volumetric light transport in a homogeneous slab. Although the symmetry of the slab allows for significant simplification, fully analytic …
doi PDF
A Position-Free Path Integral for Homogeneous Slabs and Multiple Scattering on Smith Microfacets

A bidirectional formulation for Walk on Spheres

Computer Graphics Forum, 2022

Numerically solving partial differential equations (PDEs) is central to many applications in computer graphics and scientific modeling. Conventional methods for solving PDEs often need to discretize the space first, making them less efficient for …
doi PDF Project
A bidirectional formulation for Walk on Spheres

Once-more Scattered Next Event Estimation for Volume Rendering

Computer Graphics Forum, 2022

doi PDF
Once-more Scattered Next Event Estimation for Volume Rendering

Extracting Triangular 3D Models, Materials, and Lighting From Images

IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2022

We present an efficient method for joint optimization of topology, materials and lighting from multi-view image observations. Unlike recent multi-view reconstruction approaches, which typically produce entangled 3D representations encoded in neural …
Project doi PDF
Extracting Triangular 3D Models, Materials, and Lighting From Images

Slang Shading Language Advances

Youtube, 2022

Video Slides
Slang Shading Language Advances

Research Advances Toward Real-Time Path Tracing

Game Developers Conference (GDC), 2022

Real-time graphics is on the cusp of a historic transition to path tracing, one of the largest breakthroughs for real-time graphics in many years. Path tracing is the most accurate way of rendering but is also computationally intensive due to the …
Slides
Research Advances Toward Real-Time Path Tracing

NeRF-Tex: Neural Reflectance Field Textures

Computer Graphics Forum, 2022

Abstract We investigate the use of neural fields for modelling diverse mesoscale structures, such as fur, fabric and grass. Instead of using classical graphics primitives to model the structure, we propose to employ a versatile volumetric primitive …
doi PDF Video
NeRF-Tex: Neural Reflectance Field Textures

Scalar Spatiotemporal Blue Noise Masks

ArXiv Preprint, 2021

Blue noise error patterns are well suited to human perception, and when applied to stochastic rendering techniques, blue noise masks (blue noise textures) minimize unwanted low-frequency noise in the final image. Current methods of applying blue …
Project arXiv PDF
Scalar Spatiotemporal Blue Noise Masks

Fast Volume Rendering with Spatiotemporal Reservoir Resampling

ACM Transactions on Graphics (SIGGRAPH Asia), 2021

Volume rendering under complex, dynamic lighting is challenging, especially if targeting real-time. To address this challenge, we extend a recent direct illumination sampling technique, spatiotemporal reservoir resampling, to multi-dimensional path …
Project doi PDF
Fast Volume Rendering with Spatiotemporal Reservoir Resampling

Differentiable Time-Gated Rendering

ACM Transactions on Graphics (SIGGRAPH Asia), 2021

The continued advancements of time-of-flight imaging devices have enabled new imaging pipelines with numerous applications. Consequently, several forward rendering techniques capable of accurately and efficiently simulating these devices have been …
doi PDF Presentation Supplementary Slides Code
Differentiable Time-Gated Rendering

Weighted Reservoir Sampling: Randomly Sampling Streams

Ray Tracing Gems II, 2021

Reservoir sampling is a family of algorithms that, given a stream of N elements, randomly select a K-element subset in a single pass. Usually, K is defined as a small constant, but N need not be known in advance.
doi PDF
Weighted Reservoir Sampling: Randomly Sampling Streams

Visualizing and Communicating Errors in Rendered Images

Ray Tracing Gems II, 2021

In rendering research and development, it is important to have a formalized way of visualizing and communicating how and where errors occur when rendering with a given algorithm. Such evaluation is often done by comparing the test image to a …
doi PDF Github
Visualizing and Communicating Errors in Rendered Images

The Alias Method for Sampling Discrete Distributions

Ray Tracing Gems II, 2021

The alias method is a well-known algorithm for constant-time sampling from arbitrary, discrete probability distributions that relies on a simple precomputed lookup table. We found many have never learned about this method, so we briefly introduce the …
doi PDF
The Alias Method for Sampling Discrete Distributions

Rendering Many Lights with Grid-Based Reservoirs

Ray Tracing Gems II, 2021

Efficient rendering of scenes with many lights is a longstanding problem in graphics. Sampling a light to shade from the pool of all lights, e.g., using next event estimation, is a nontrivial task. Sampling must be computationally efficient, must …
doi PDF
Rendering Many Lights with Grid-Based Reservoirs

Refraction Ray Cones for Texture Level of Detail

Ray Tracing Gems II, 2021

Texture filtering is an important implementation detail of every rendering system. Its purpose is to achieve high-quality rendering of textured surfaces, while avoiding artifacts, such as aliasing, Moire patterns, and unnecessary overblur. In this …
Project doi PDF
Refraction Ray Cones for Texture Level of Detail

Differential Barycentric Coordinates

Ray Tracing Gems II, 2021

We describe an optimized way to compute differential barycentric coordinates, which can be employed by implementations of ray differentials. This technique can be used for texture fltering computations for ray tracing.
Project doi PDF
Differential Barycentric Coordinates

An Unbiased Ray-Marching Transmittance Estimator

ACM Transactions on Graphics (SIGGRAPH), 2021

We present an in-depth analysis of the sources of variance in state-of-the-art unbiased volumetric transmittance estimators, and propose several new methods for improving their efficiency. These combine to produce a single estimator that is …
Project doi PDF
An Unbiased Ray-Marching Transmittance Estimator

Rearchitecting Spatiotemporal Resampling for Production

ACM/EG Symposium on High Performance Graphics (HPG), 2021

Recent work by Bitterli et al. introduced a real-time, many-light algorithm for rendering dynamic direct illumination from millions of lights by iteratively applying resampled importance sampling using weighted reservoir sampling. While enabling new …
doi PDF Video
Rearchitecting Spatiotemporal Resampling for Production

Real-Time Neural Radiance Caching for Path Tracing

ACM Transactions on Graphics (SIGGRAPH), 2021

We present a real-time neural radiance caching method for path-traced global illumination. Our system is designed to handle fully dynamic scenes, and makes no assumptions about the lighting, geometry, and materials. The data-driven nature of our …
doi PDF Video Results
Real-Time Neural Radiance Caching for Path Tracing

Neural Scene Graph Rendering

ACM Transactions on Graphics (SIGGRAPH), 2021

We present a neural scene graph—a modular and controllable representation of scenes with elements that are learned from data. We focus on the forward rendering problem, where the scene graph is provided by the user and references learned …
doi PDF Video Supplementary
Neural Scene Graph Rendering

Zero-variance Transmittance Estimation

Eurographics Symposium on Rendering, 2021

We apply zero-variance theory to the Volterra integral formulation of volumetric transmittance. We solve for the guided sampling decisions in this framework that produce zero-variance ratio tracking and next-flight ratio tracking estimators. In both …
doi PDF Video
Zero-variance Transmittance Estimation

Vectorization for Fast, Analytic, and Differentiable Visibility

ACM Transactions on Graphics (ToG), 2021

In Computer Graphics, the two main approaches to rendering and visibility involve ray tracing and rasterization. However, a limitation of both approaches is that they essentially use point sampling. This is the source of noise and aliasing, and also …
doi PDF Video Presentation
Vectorization for Fast, Analytic, and Differentiable Visibility

ReSTIR GI: Path Resampling for Real-Time Path Tracing

ACM/EG Symposium on High Performance Graphics (HPG), 2021

Even with the advent of hardware-accelerated ray tracing in modern GPUs, only a small number of rays can be traced at each pixel in real-time applications. This presents a significant challenge for path tracing, even when augmented with state-of-the …
Project doi PDF
ReSTIR GI: Path Resampling for Real-Time Path Tracing

Visualizing Errors in Rendered High Dynamic Range Images

Eurographics (Short Papers), 2021

A new error metric targeting rendered high dynamic range images is presented. Our method computes a composite visualization over a number of low dynamic range error maps of exposure compensated and tone mapped image pairs with automatically computed, …
doi PDF Supplemental Video Github
Visualizing Errors in Rendered High Dynamic Range Images

Appearance-Driven Automatic 3D Model Simplification

Eurographics Symposium on Rendering, 2021

We present a suite of techniques for jointly optimizing triangle meshes and shading models to match the appearance of reference scenes. This capability has a number of uses, including appearance-preserving simplification of extremely complex assets, …
doi PDF Video Code
Appearance-Driven Automatic 3D Model Simplification

Interactive Path Tracing and Reconstruction of Sparse Volumes

ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D), 2021
🏆 Best Paper Presentation

Denoisers designed for surface geometry rely on noise-free feature guides for high quality results. However, these guides are not readily available for volumes. Our method enables combined volume and surface denoising in real time from low sample …
doi PDF Video
Interactive Path Tracing and Reconstruction of Sparse Volumes

Improved Shader and Texture Level of Detail Using Ray Cones

Journal of Computer Graphics Techniques, 2021

In real-time ray tracing, texture filtering is an important technique to increase image quality. Current games, such as Minecraft with RTX on Windows 10, use ray cones to determine texture-filtering footprints. In this paper, we present several …
Project PDF
Improved Shader and Texture Level of Detail Using Ray Cones

Neural Control Variates

ACM Transactions on Graphics (SIGGRAPH Asia), 2020

We propose neural control variates (NCV) for unbiased variance reduction in parametric Monte Carlo integration. So far, the core challenge of applying the method of control variates has been finding a good approximation of the integrand that is cheap …
doi PDF Video Results
Neural Control Variates

Glossy Probe Reprojection for Interactive Global Illumination

ACM Transactions on Graphics (SIGGRAPH Asia), 2020

Recent rendering advances dramatically reduce the cost of global illumination. But even with hardware acceleration, complex light paths with multiple glossy interactions are still expensive; our new algorithm stores these paths in precomputed light …
Project doi PDF
Glossy Probe Reprojection for Interactive Global Illumination

Compositional Neural Scene Representations for Shading Inference

ACM Transactions on Graphics (SIGGRAPH), 2020

We present a technique for adaptively partitioning neural scene representations. Our method disentangles lighting, material, and geometric information yielding a scene representation that preserves the orthogonality of these components, improves …
doi PDF Video Code
Compositional Neural Scene Representations for Shading Inference

Spatiotemporal Reservoir Resampling for Real-time Ray Tracing with Dynamic Direct Lighting

ACM Transactions on Graphics (SIGGRAPH), 2020

Efficiently rendering direct lighting from millions of dynamic light sources using Monte Carlo integration remains a challenging problem, even for off-line rendering systems. We introduce a new algorithm—ReSTIR—that renders such lighting …
doi PDF Video Presentation Supplementary Promotional video
Spatiotemporal Reservoir Resampling for Real-time Ray Tracing with Dynamic Direct Lighting

ꟻLIP: A Difference Evaluator for Alternating Images

Proceedings of the ACM on Computer Graphics and Interactive Techniques, 2020
🏆 3rd Best Paper

Image quality measures are becoming increasingly important in the field of computer graphics. For example, there is currently a major focus on generating photorealistic images in real time by combining path tracing with denoising, for which such …
doi PDF Supplemental Video Github Project
ꟻLIP: A Difference Evaluator for Alternating Images

A Survey of Temporal Antialiasing Techniques

Computer Graphics Forum, 2020

Abstract Temporal Antialiasing (TAA), formally defined as temporally-amortized supersampling, is the most widely used antialiasing technique in today’s real-time renderers and game engines. This survey provides a systematic overview of this …
doi PDF
A Survey of Temporal Antialiasing Techniques

Understanding SSIM

ArXiv Preprint, 2020

The use of the structural similarity index (SSIM) is widespread. For almost two decades, it has played a major role in image quality assessment in many different research disciplines. Clearly, its merits are indisputable in the research community. …
Project arXiv PDF
Understanding SSIM

Practical Product Sampling by Fitting and Composing Warps

Eurographics Symposium on Rendering, 2020

We introduce a Monte Carlo importance sampling method for integrands composed of products and show its application to rendering where direct sampling of the product is often difficult. Our method is based on warp functions that operate on the primary …
doi PDF
Practical Product Sampling by Fitting and Composing Warps

Neural Denoising with Layer Embeddings

Computer Graphics Forum, 2020

We propose a novel approach for denoising Monte Carlo path traced images, which uses data from individual samples rather than relying on pixel aggregates. Samples are partitioned into layers, which are filtered separately, giving the network more …
doi PDF Code
Neural Denoising with Layer Embeddings

Neural Temporal Adaptive Sampling and Denoising

Computer Graphics Forum, 2020

Despite recent advances in Monte Carlo path tracing at interactive rates, denoised image sequences generated with few samples per-pixel often yield temporally unstable results and loss of high-frequency details. We present a novel adaptive rendering …
doi PDF Video
Neural Temporal Adaptive Sampling and Denoising

Ray Tracing Gems

Book from APress, 2019

Project
Ray Tracing Gems

Temporally Dense Ray Tracing

ACM/EG Symposium on High Performance Graphics (HPG; Short Papers), 2019

We present a technique for real-time ray tracing with the goal of reaching 240 frames per second or more. The core idea is to trade spatial resolution for faster temporal updates in such a way that the display and human visual system aid in …
doi PDF Supplemental
Temporally Dense Ray Tracing

Introduction to Real-Time Ray Tracing

ACM SIGGRAPH Courses, 2019

Project doi
Introduction to Real-Time Ray Tracing

Dynamic Many-Light Sampling for Real-Time Ray Tracing

ACM/EG Symposium on High Performance Graphics (HPG), 2019

Monte Carlo ray tracing offers the capability of rendering scenes with large numbers of area light sources-lights can be sampled stochastically and shadowing can be accounted for by tracing rays, rather than using shadow maps or other …
doi PDF
Dynamic Many-Light Sampling for Real-Time Ray Tracing

What is a Ray?

Ray Tracing Gems, 2019

We define a ray, show how to use ray intervals, and demonstrate how to specify a ray using DirectX Raytracing (DXR).
Project doi
What is a Ray?

Texture Level of Detail Strategies for Real-Time Ray Tracing

Ray Tracing Gems, 2019

Unlike rasterization, where one can rely on pixel quad partial derivatives, an alternative approach must be taken for filtered texturing during ray tracing. We describe two methods for computing texture level of detail for ray tracing. The first …
Project doi
Texture Level of Detail Strategies for Real-Time Ray Tracing

Simple Environment Map Filtering Using Ray Cones and Ray Differentials

Ray Tracing Gems, 2019

We describe simple methods for how to filter environment maps using ray cones and ray differentials in a ray tracing engine.
Project doi
Simple Environment Map Filtering Using Ray Cones and Ray Differentials

Precision Improvements for Ray/Sphere Intersection

Ray Tracing Gems, 2019

The traditional quadratic formula is often presented as the way to compute the intersection of a ray with a sphere. While mathematically correct, this factorization can be numerically unstable when using floating-point arithmetic. We give two …
Project doi
Precision Improvements for Ray/Sphere Intersection

Immersive Linear Algebra

Book from Free online, interactive book, 2019

Project
Immersive Linear Algebra

Sample Transformations Zoo

Ray Tracing Gems, 2019

We present several formulas and methods for generating samples distributed according to a desired probability density function on a specific domain. Sampling is a fundamental operation in modern rendering, both at runtime and in preprocessing. It is …
doi PDF
Sample Transformations Zoo

Introduction to DirectX Raytracing

Ray Tracing Gems, 2019

Modern graphics APIs such as DirectX 12 expose low-level hardware access and control to developers, often resulting in complex and verbose code that can be intimidating for novices. In this chapter, we hope to demystify the steps to set up and use …
doi PDF
Introduction to DirectX Raytracing

Improved Alpha Testing Using Hashed Sampling

IEEE Transactions on Visualization and Computer Graphics (TVCG), 2019

We further describe and analyze the idea of hashed alpha testing from Wyman and McGuire, which builds on stochastic alpha testing and simplifies stochastic transparency. Typically, alpha testing provides a simple mechanism to mask out complex …
doi PDF
Improved Alpha Testing Using Hashed Sampling

Importance Sampling of Many Lights on the GPU

Ray Tracing Gems, 2019

The introduction of standardized APIs for ray tracing, together with hardware acceleration, opens up possibilities for physically based lighting in real-time rendering. Light importance sampling is one of the fundamental operations in light transport …
doi PDF
Importance Sampling of Many Lights on the GPU

Efficient Generation of Points that Satisfy Two-Dimensional Elementary Intervals

Journal of Computer Graphics Techniques, 2019

Precomputing high-quality sample points has been shown to be a useful technique for Monte Carlo integration in rendering; doing so allows optimizing properties of the points without the performance constraints of generating samples during rendering. …
PDF
Efficient Generation of Points that Satisfy Two-Dimensional Elementary Intervals

A Ray-Box Intersection Algorithm and Efficient Dynamic Voxel Rendering

Journal of Computer Graphics Techniques, 2018

We introduce a novel and efficient method for rendering large models composed of individually-oriented voxels. The core of this method is a new algorithm for computing the intersection point and normal of a 3D ray with an arbitrarily-oriented 3D box, …
Project PDF Code
A Ray-Box Intersection Algorithm and Efficient Dynamic Voxel Rendering

Real-Time Rendering, 4th Ed.

Book from CRC Press, 2018

Project
Real-Time Rendering, 4th Ed.

Introduction to DirectX Ray Tracing

ACM SIGGRAPH Courses, 2018

Project doi
Introduction to DirectX Ray Tracing

Correlation-Aware Semi-Analytic Visibility for Antialiased Rendering

ACM/EG Symposium on High Performance Graphics (HPG), 2018

Geometric aliasing is a persistent challenge for real-time rendering. Hardware multisampling remains limited to 8x, analytic coverage fails to capture correlated visibility samples, and spatial and temporal postfiltering primarily target edges of …
doi PDF Project
Correlation-Aware Semi-Analytic Visibility for Antialiased Rendering

Noise2Noise: Learning image restoration without clean data

International Conference on Machine Learning (ICML), 2018

We apply basic statistical reasoning to signal reconstruction by machine learning — learning to map corrupted observations to clean signals — with a simple and powerful conclusion: under certain common circumstances, it is possible to learn to …
PDF
Noise2Noise: Learning image restoration without clean data

Spatiotemporal Variance-Guided Filtering: Real-time Reconstruction for Path Traced Global Illumination

ACM/EG Symposium on High Performance Graphics (HPG), 2017
🏆 Best Paper

We introduce a reconstruction algorithm that generates a temporally stable sequence of images from one path-per-pixel global illumination. To handle such noisy input, we use temporal accumulation to increase the effective sample count and …
doi PDF Video Code Project
Spatiotemporal Variance-Guided Filtering: Real-time Reconstruction for Path Traced Global Illumination

Interactive Stable Ray Tracing

ACM/EG Symposium on High Performance Graphics (HPG), 2017

Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and …
Project doi PDF
Interactive Stable Ray Tracing

Interactive Reconstruction of Monte Carlo Image Sequences Using a Recurrent Denoising Autoencoder

ACM Transactions on Graphics (SIGGRAPH), 2017

We describe a machine learning technique for reconstructing image sequences rendered using Monte Carlo methods. Our primary focus is on reconstruction of global illumination with extremely low sampling budgets at interactive rates. Motivated by …
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Interactive Reconstruction of Monte Carlo Image Sequences Using a Recurrent Denoising Autoencoder

Generating Stratified Random Lines in a Square

Journal of Computer Graphics Techniques, 2017

When generating a set of uniformly distributed lines through a square, some care is needed to avoid bias in line orientation and position. We present a compact algorithm to generate unbiased uniformly distributed lines from a uniform point set over …
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Generating Stratified Random Lines in a Square

Hashed Alpha Testing

ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D), 2017

Renderers apply alpha testing to mask out complex silhouettes using alpha textures on simple proxy geometry. While widely used, alpha testing has a long-standing problem that is underreported in the literature, but observable in commercial games: …
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Hashed Alpha Testing

Towards Foveated Rendering for Gaze-Tracked Virtual Reality

ACM Transactions on Graphics (SIGGRAPH Asia), 2016

Foveated rendering synthesizes images with progressively less detail outside the eye fixation region, potentially unlocking significant speedups for wide field-of-view displays, such as head mounted displays, where target framerate and resolution is …
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Towards Foveated Rendering for Gaze-Tracked Virtual Reality

Frustum-Traced Irregular Z-Buffers: Fast, Sub-pixel Accurate Hard Shadows

IEEE Transactions on Visualization and Computer Graphics (TVCG), 2016

We further describe and analyze a real-time system for rendering antialiased hard shadows using irregular z-buffers (IZBs) that we first presented in Wyman et al.. We focus on identifying bottlenecks, exploring these from an algorithmic complexity …
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Frustum-Traced Irregular Z-Buffers: Fast, Sub-pixel Accurate Hard Shadows

Perceptually-based Foveated Virtual Reality

ACM SIGGRAPH Emerging Technologies, 2016

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Exploring and Expanding the Contiuum of OIT Algorithms

ACM/EG Symposium on High Performance Graphics (HPG), 2016

Order independent transparency (OIT) proves challenging for modern rasterization-based renderers. Rendering without transparency can limit the quality of visual effects, so researchers have proposed various algorithms enabling and approximating OIT. …
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Exploring and Expanding the Contiuum of OIT Algorithms

CloudLight: A System for Amortizing Indirect Lighting in Real-Time Rendering

Journal of Computer Graphics Techniques, 2015

This paper describes the CloudLight system for computing indirect lighting asynchronously on an abstracted, computational “cloud,” in support of real-time rendering for interactive 3D applications on a local client device. We develop and …
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CloudLight: A System for Amortizing Indirect Lighting in Real-Time Rendering

The SGGX microflake distribution

ACM Transactions on Graphics (SIGGRAPH), 2015

We introduce the Symmetric GGX (SGGX) distribution to represent spatially-varying properties of anisotropic microflake participating media. Our key theoretical insight is to represent a microflake distribution by the projected area of the …
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The SGGX microflake distribution

Decoupled Coverage Anti-Aliasing

ACM/EG Symposium on High Performance Graphics (HPG), 2015

State-of-the-art methods for geometric anti-aliasing in real-time rendering are based on Multi-Sample Anti-Aliasing (MSAA), which samples visibility more than shading to reduce the number of expensive shading calculations. However, for high-quality …
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Decoupled Coverage Anti-Aliasing

An Overview of Next-Generation Graphics APIs

ACM SIGGRAPH Courses, 2015

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Aggregate G-Buffer Anti-Aliasing

ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D), 2015

We present Aggregate G-Buffer Anti-Aliasing (AGAA), a new technique for efficient anti-aliased deferred rendering of complex geometry using modern graphics hardware. In geometrically complex situations, where many surfaces intersect a pixel, current …
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Aggregate G-Buffer Anti-Aliasing

Frustum-Traced Raster Shadows: Revisiting Irregular Z-Buffers

ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D), 2015
🏆 Best Paper

We present a real-time system that renders antialiased hard shadows using irregular z-buffers. For subpixel accuracy, we use 32 samples per pixel at roughly twice the cost of a single sample. Our system remains interactive on a variety of game assets …
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Frustum-Traced Raster Shadows: Revisiting Irregular Z-Buffers

Simple Analytic Approximations to the CIE XYZ Color Matching Functions

Journal of Computer Graphics Techniques, 2013

We provide three analytical fits to the CIE x, y, and z color matching curves, commonly used in predictive and spectral renderers as an intermediate between light spectra and RGB colors. Any can replace the standard CIE curves, which come tabulated. …
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Simple Analytic Approximations to the CIE XYZ Color Matching Functions

Imperfect Voxelized Shadow Volumes

ACM/EG Symposium on High Performance Graphics (HPG), 2013

Voxelized shadow volumes provide a discretized view-dependent representation of shadow volumes, but are limited to point or directional lights. We extend them to allow dynamic volumetric visibility from area light sources using imperfect shadow …
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Imperfect Voxelized Shadow Volumes

Octree-Based Sparse Voxelization Using The GPU Hardware Rasterizer

OpenGL Insights, 2012

Discrete voxel representations are generating growing interest in a wide range of applications in computational sciences and particularly in computer graphics. In this chapter, we first describe an efficient OpenGL implementation of a simple surface …
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Octree-Based Sparse Voxelization Using The GPU Hardware Rasterizer

Interactive Indirect Illumination Using Voxel Cone Tracing

Computer Graphics Forum (Pacific Graphics), 2011

Indirect illumination is an important element for realistic image synthesis, but its computation is expensive and highly dependent on the complexity of the scene and of the BRDF of the involved surfaces. While off-line computation and pre-baking can …
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Interactive Indirect Illumination Using Voxel Cone Tracing