“Path Guiding in Production and Recent Advancements” by Herholz, Šik, Reichardt and Manzi
Conference:
Type(s):
Title:
- Path Guiding in Production and Recent Advancements
Organizer(s):
Presenter(s)/Author(s):
Abstract:
Over the last decade, advanced data-driven sampling algorithms such as path guiding made their way from the scientific realm into production renderers. These algorithms make it possible to render challenging lighting effects (e.g., complex indirect illumination, caustics, volumetric multi-scattering, occluded direct illumination from many lights), which are crucial when generating high-fidelity images. The fact that these algorithms mainly focus on optimizing local importance sampling decisions makes it possible to integrate them into a path tracer, the de facto standard rendering algorithm used in production nowadays. The theory behind these algorithms has been presented and discussed on various occasions (e.g., in presentations or research papers) and their usefulness in production has been presented in the previous course on \emph{path guiding in production}. Nevertheless, the implementation details or challenges when integrating them into a production render are usually unknown or not discussed publicly. This course aims to give more profound insights into how some of these guiding algorithms are integrated into and used in different production renderers, such as Cycles, Manuka, VRay, Corona, Karma, and Hyperion. The presented algorithms and integrations can be separated into two categories: the first aims to guide the entire sampling process by using information about the total light transport of the scene, and the second focuses on guiding specific effects like caustic.
Additional Information:
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- Short introduction to the concepts of path guiding
- Summary of recent advancement since the last course
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- Presentation of multiple insights and details to integrate path guiding in a production renderer:
- Integration of guided directional sampling
- Light Path Expressions and path guiding
- Efficient guiding combined with direct light sampling
- Path guiding and Russian Roulette
- Presentation of multiple insights and details to integrate path guiding in a production renderer:
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- Integrating Path guiding into a wavefront renderer (i.e., Hyperion)
- Experiences with path guiding in production
- Challenges of recording training data for path guiding when using a wavefront renderer
- How to debug your path guiding implementation/integration
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- Showcasing the limitations of traditional path guiding when rendering caustics
- Presentation of a specialized VCM-based solution for rendering caustics that uses a guiding approach for distributing photons
Intermediate
Prerequisite: Fundamental knowledge about rendering, especially path tracing.
Topics: Lighting, Machine Learning, Rendering, Path Tracing
List of topics and approximate times:
Introduction (5-10min) Sebastian Herholz
Integrating Path guiding into a production render: The Nitty Gritty Details (30min) Sebastian Herholz
Path Guiding in Hyperion: A case study (30min) Lea Reichardt and Marco Manzi
Efficient Rendering of Caustics: Photon Guiding at Corona (20-25min) Martin Šik
Additional Info: We will share some nitty-gritty details and challenges when integrating path guiding into production rendering systems.
