Ray Tracing from the Ground Up

Chapter 18

Area Lights

Objectives

By the end of this chapter, you should:

• understand how area lights are modeled and rendered;
• have implemented a number of area lights;
• have implemented an environment light.

All real light sources have finite area, and as such, their illumination and soft shadows can add great realism to your images. This is in contrast to the sharp-edged shadows that we get from point and directional lights. The price we have to pay is more sample points per pixel and longer rendering times, but the results are worth it.

I’ll discuss here a flexible lighting architecture that will allow you to use a variety of geometric objects ...