Part III. Illumination

One of the most important aspects of rendering is lighting. Thus far, all of our objects have had a color that is entirely part of the mesh data, pulled from a uniform variable, or computed in an arbitrary way. This makes all of our objects look very flat and unrealistic.

Properly modeling the interaction between light and a surface is vital in creating a convincing world. Lighting defines how we see and understand shapes to a large degree. The lack of lighting is the reason why the objects we have used thus far look fairly flat. A curved surface appears curved to us because of how the light plays over the surface. The same goes for a flat surface.

Without this visual hinting, surfaces appear flat even when they are modeled with many triangles and yield a seemingly-curved polygonal mesh. A proper lighting model makes objects appear real. A poor or inconsistent lighting model shows the virtual world to be the forgery that it is.

This section of the book will cover lighting, using a variety of light/surface modelling techniques. It will cover dynamic range and linear colorspaces in lighting equations. Also, it will cover techniques to use lighting to produce entirely fake surfaces.

Fork me on GitHub