Having explored the fundamental concepts of light, color perception, and digital color representation, we now turn to the practical question of how to structure a ray tracing program. The object-oriented approach provides a natural way to model the components of a ray tracing system.
At the heart of any ray tracing system are several fundamental classes that represent the basic building blocks:
Class relationship diagram showing the structure of our core classes. The Ray class contains two Vector3D instances (origin and direction) and one Color instance, while Vector3D and Color each encapsulate three numerical values.
Before we can implement these classes, we need a solid foundation in vector mathematics. Vectors are essential for representing:
Our vector operations will include addition, subtraction, dot products, cross products, and normalization. These mathematical operations form the backbone of all ray-object intersection calculations and lighting computations. More on vectors in the next page.
A Ray consists of an origin point (Vector3D), a direction vector (Vector3D), and a color (Color). These three components together represent a virtual ray of light in 3D space.
Our Color class uses floating-point values ranging from 0.0 to 1.0 for each RGB component, rather than the traditional 0-255 integer range. This approach provides several advantages for ray tracing calculations.
In this model, a color value of (1.0, 1.0, 1.0) represents full white, equivalent to #ffffff in traditional HTML color notation. However, unlike traditional color systems, our Color model can and will represent values greater than 1.0 in many cases. These "super-bright" colors are essential for realistic lighting calculations, where light sources and reflections can produce intensities that exceed the standard display range.
For example, a color value of (2.5, 1.8, 1.2) might represent a bright light source or a highly reflective surface that appears much brighter than pure white. These values will be clamped to the displayable range when converting to final output, but maintaining the full range during calculations preserves the accuracy of our lighting model.
By starting with these three fundamental classes, we can build a ray tracing system step by step. The Vector3D class provides the mathematical foundation, the Ray class represents the light paths we'll trace, and the Color class manages the visual output.
This modular approach means we can test and refine each component independently before combining them into more complex systems. We can also extend and modify these classes as our understanding and requirements evolve.
In the following pages, we'll implement these concepts step by step, starting with the fundamental Vector3D class that will support all our geometric calculations.