The SEDRIS Data Representation Model
APPENDIX A - Classes
Diffuse Colour

Class Name: Diffuse Colour

Superclass - <SEDRIS Abstract Base>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies the diffuse reflectance component of a <Primitive Colour>.

<Diffuse Colour> is

Surfaces exhibiting only diffuse reflection (also known as Lambertian reflection) are dull, matte surfaces that appear equally bright from all viewing angles. When a beam of light is reflected from such a surface, the reflected ray is diffused to cover an area, the size of which is inversely proportional to the cosine of the angle that the beam makes with the surface normal.

Diffuse reflection provides what is known as "shape from shading" information to visual perception; that is, for a surface composed of a single substance and illuminated by a single light source, the shading of the object can be used to compute its surface normals (i.e., its shape).

See [FOLEY_VAN_DAM] 16.1.2, "Diffuse Reflection" for further discussion of diffuse reflectance.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

See <Primitive Colour>.

FAQs

Does SEDRIS use the OpenGL lighting model?

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

Constraints

None.

Composed of (two-way)

Component of (two-way)

Inherited Field Elements

This class has no inherited field elements.
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Last updated: October 1, 2002 Copyright © 2002 SEDRIS™