This repository contains a collection of materials describing PhysLight. PhysLight is a philosophy as much as a method. This means that there is not one simple plugin to install to "get" PhysLight.
The documentation contained in /docs describes the conceptual background and
mathematical foundation which are the basis for PhysLight.
It also has fully worked out numerical examples of various common configurations
that people can use to double-check their work, together with indications and
reference code segments for all the algorithms and methods described.
We keep a PDF build of the docs right in the docs directory
Our latest full PDF build is here corresponding to our in-progress v1.3 sprint on the documentation.
No changes are happening to the definitions, but all the document is being worked on and edited for clarity in hopes to make it more useful for people. Feedback is very welcome
A higher level overview of the PhysLight system was presented in the Siggraph 2020 Talk PhysLight: An End-to-End Pipeline for Scene-Referred Lighting. Slides can be found here.
In the usd folder are a set of schema that can be used to apply to lights and cameras in USD to store and carry necessary information to implement a system that communicates lights and camera data necessary to implement a PhysLight compliant render chain.
The data directory contains the spectral sensitivity curves of a number of cameras as measured with our 'lightsaber' system. It also contains a notebook that loads the data and plots the curves for visual inspection.
The imaging notebook shows a simple example of calculating the imaging ratio and checking that it gives the correct response for an idealized camera system.
The physlight camera model notebook shows how to use the curves to convert from spectral radiance to Camera RGB, solve matrices to go from Camera RGB to XYZ, and compares different approaches for handling white balance.
