Class Name: Ambient Colour

Superclass - <SEDRIS Abstract Base>

Subclasses

Definition

An instance of this DRM class specifies the ambient reflectance component of a <Primitive Colour> instance or <Light Source> instance, providing the base colour to the lighting equation for the object being lit or the light itself, respectively.

Ambient light is the result of bouncing light rays around the environment until the light has been diffused so much that its source and direction cannot be determined. Consequently, an <Ambient Colour> instance is

1. independent of the angle of the lit object to the light source
2. independent of the angle of the lit object to the observer

The <Ambient Colour> instance of an environmental object is combined with the ambient component of each incoming light source to determine the colour due to the ambient light.

Primary Page in DRM Diagram:

• 14

Secondary Pages in DRM Diagram:

• 21

Example

See the <Primitive Colour> class for examples.

FAQs

Does the DRM use the OpenGL lighting model?

No, although the terminology is similar. The DRM handles transparency somewhat differently than OpenGL does, among other things. For a description of the OpenGL lighting model, see [OPENGL], Chapter 5 "Lighting".

Constraints

• <<Publishable Object>>

Composed of (two-way)

• one <Colour Data> instance

Component of (two-way)

• zero or one <Light Source> instance
• zero or one <Primitive Colour> instance

Inherited Field Elements