Blog 3: Lighting

Lighting

What is Lighting used for?               

In-game lighting can change and create a different atmosphere of the area that is being lit. Simulating lights the the game can make the objects and the scenes more realistic rather than being stale and plain. Lighting can be used to draw attention to a certain object, person or scene.

Types of Lights

Specular Light

Specular light is the bright spot of the light that appears to make the object shiny. Specular light in computer graphics help make the 3D object look more realistic by giving the object a more reflective look. The specular light is used to determine the intensity by calculating the reflected light ray and the camera location.

Ambient Light

Ambient light is the amount of lighting in the scene. Ambient light is a soft indirect light that softens shadows and fills the scene with illumination. Ambient light is mainly used to provide the scene with a basic view of different objects.

Diffuse Light

Diffuse light is light that fills up the remaining area of the object or scene that the specular light does not hit. 

http://www.beyond3d.com/images/articles/Geometry/lighting-specular-sphere.gif

Emissive Light

Emissive light is a light that is emitting from an object in the scene. The emissive light is used to help make your objects or scene to be more realistic. Without emissive lights your objects or scene could look plain.

Per-Face vs. Per-Vertex vs. Per-Pixel

Per-Face

Per-Face lighting is calculating the amount of light that is hitting the object per face. The light intensity changes per face, making the object look blocky and rough. 

Per-Vertex

Per-Vertex lighting calculates the light that hits per-vertex. Next, it interpolates between the vertices and taking the average of lighting between each vertex.

Per-Pixel

Per-Pixel lighting calculate the light that hits per-pixel. Per-pixel lighting has the best result of the 3 because the program has more information to work with; resulting in giving the object a sharper look.