Artefact 1 - Lighting

This is the first artefact from my research paper. In it I stated that I will produce the artefacts in the following format;

"Lighting – The first artefact will be a series of rendered shots showing how the different styles of lighting affect the same object. These will be with and without global illumination, with and without radiosity, with and without ray tracing."

The first part of this artefact that should be taken into account is the global illumination principle. This is the process of calculating the direction and intensity of the light that bounces of the objects in the scene. It should be noted that both radiosity and ray tracing are used in global illumination but both will be explained in more detail. The goal of global illumination is to recreate the light and feel of an environment as if you were standing in a real world equivalent.

There are 2 types of illumination, direct and indirect. Direct illumination is the light that hits a surface directly from the light source and indirect illumination is the light that bounces off a surface onto another surface. Indirect illumination is what creates the shadows in the scene. Radiosity and ray tracing are algorithms that help calculate indirect illumination. As you can see, from the radiosity and ray tracing examples, when there is no indirect illumination no shadows are calculated. This is because radiosity and ray tracing algorithms calculate the bounce on the light off other surfaces and the strength of the light that is reflected onto other surfaces.

Ray tracing is the more efficient way of calculating the light rays. The ray is traced back from the virtual camera to the objects and environment to the original light source. This saves on memory as you are only seeing the necessary light. It does however have some disadvantages. It doesn’t account for light that has bounced off other surfaces so the shadows appear as black blocks. This is why you have to combine it with radiosity to get a better overall aspect of global illumination.

Radiosity calculates the reflections on surfaces from the light source and from other surfaces. It breaks down the surfaces into smaller elements and then calculates how much light is transferred from one element to another.

Both these techniques can be combines to create a better illumination of the scene. The more reflections and rays that you trace and calculate the more detailed and accurate the scene will become.