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The SEDRIS Data Representation Model
APPENDIX A - Classes Diffuse Colour |
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An instance of this DRM class specifies the diffuse reflectance component of a <Primitive Colour> instance.
A <Diffuse Colour> instance is dependent on the angle of the lit environmental object to the light source but independent of the angle of the lit environmental object to the observer.
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.
NOTE Diffuse reflection provides what is known as shape from shading information to visual perception. 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 (that is, its shape).
See 16.1.2 Diffuse Reflection of [Foley] for further discussion of diffuse reflectance.
See the <Primitive Colour> class for examples.
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".
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