![]() ![]() Out-scattering: photons making up our narrow beam are traveling in the direction -\(\omega\), directly towards the eye, however, they might not reach the eye because some there will be scattered along the way in another (random) direction. Our narrow (collimated) light beam passing through a cylinder can interact with the medium in four different ways (assuming our small cylinder is of course not empty but filled with some particles):Ībsorption: some of the light is absorbed. In our code, this is the camera ray direction. The view direction is denoted \(\omega\) (the Greek letter omega). \(L_o\) is the outgoing radiance: how much leave the volume on the other end. \(L_i\) is the incoming radiance: the intensity of the light beam shone on the cylinder. The technical term for his light quantity is radiance which we will denote with the letter \(L\). What we are looking for, is the intensity of that light beam (how much light reaches the viewer's eyes) after it has traveled through the volume. A viewer is looking down at this cylinder from one end and we shine a collimated beam of light on the other end as depicted in the image below. Volumes are often represented as small differential cylinders. So it's a good idea to get familiarized with these conventions. Most books and papers use the same conventions when it comes to rendering in general and rending participating media (plural of medium) in particular. # How does light interact with a participating medium and propagate in volumes? If you are not interested in the theory at all, then you can skip this chapter (stick to the first four chapters of this lesson that are just about practice). In this chapter, we will learn about the equations that govern volume rendering. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |