O'Reilly logo

Physically Based Rendering, 3rd Edition by Greg Humphreys, Wenzel Jakob, Matt Pharr

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

05

Color and Radiometry

In order to precisely describe how light is represented and sampled to compute images, we must first establish some background in radiometry—the study of the propagation of electromagnetic radiation in an environment. Of particular interest in rendering are the wavelengths (λ) of electromagnetic radiation between approximately 380 nm and 780 nm, which account for light visible to humans.1 The lower wavelengths (λ ≈ 400 nm) are the bluish colors, the middle wavelengths (λ ≈ 550 nm) are the greens, and the upper wavelengths (λ ≈ 650 nm) are the reds.

In this chapter, we will introduce four key quantities that describe electromagnetic radiation: flux, intensity, irradiance, and radiance. These radiometric quantities are ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required