Physically based rendering from first principles

Summary

Physically based rendering from first principles In this interactive article, we will explore the physical phenomena that create light and the fundamental laws governing its interaction with matter. We will learn how our human eyes capture light and how our brains interpret it as visual information. We will then model approximations of these physical interactions and learn how to create physically realistic renderings of various materials. Chapter 1: What is light? We are all familiar with light: it’s the thing that allows us to see the world, distinguish colors and textures, and keeps the universe from being a dark, lifeless void. But precisely defining what light is has proven to be a tricky question. Throughout history, many philosophers (and later, physicists) studied light in an effort to demystify its nature. Some ancient Greeks considered it to be one of the four fundamental elements that composed the universe: beams of fire emanating from our eyes. Descartes proposed that light behaved like waves, while Newton thought that it consisted of tiny particles of matter called corpuscles. Each of these more or less scientific theories explained some aspects of light's behavior, but none could account for all of them in a single, unified framework. That was until the 1920s when physicists came up with quantum electrodynamics. This theory is, as of now, the most accurate way to describe every interaction of light and matter. You can hover the diagram below to see which light's phenomena can be explained using each model: Reflection / Refraction / Transmission Diffraction Interference Polarization Dispersion Fluorescence Phosphorescence For the purpose of computer graphics, the ray optics model is accurate enough at simulating light interactions. But for the sake of scientific curiosity, we will explore some aspects of the other models, starting with electromagnetism. The Electric force One of the fundamental properties of matter is the electric charge, and it comes i...