Notes of Real-Time Rendering Chapter 9
Physics of Light
The interactions of light and matter form the foundation of physically based shading.
In physical optics, light is modeled as an electromagnetic transverse wave(横波), a wave that oscillates(振荡) the electric and magnetic fields perpendicularly(垂直) to the direction of its propagation.
The magnetic and electric field vectors are perpendicular to each other and the ratio of their lengths is fixed. This ratio is equal to hte phase velocity.
Light with a single wavelength is called monochromatic(单色) light. Most light waves encountered in practice are polychromatic(多色).
In unpolarized(偏振) light the field oscillations are spread equally over all directions perpendicular to the propagation axis.