The SEDRIS Data Representation Model
APPENDIX A - Classes
Lobe Data

Class Name: Lobe Data

Superclass - <SEDRIS Abstract Base>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class describes a cone or a pyramid shape of a light source or directional light in terms of direction vectors for the central axis (light direction), the vertical axis, and horizontal and vertical angular widths.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

See examples in: <Spot Light>, <Blend Directional Light>, <Cone Directional Light>, and <Pyramid Directional Light>.

FAQs

If the two <Reference Vector> components specify the light direction and vertical axis, how is the horizontal axis specified?

The horizontal direction is always perpendicular to the plane of the two <Reference Vectors> of type SE_REF_VEC_TYP_LIGHT_DIRECTION and SE_REF_VEC_TYP_VERTICAL_AXIS.

Constraints

Composed of (two-way)

Component of (two-way)

Inherited Field Elements

This class has no inherited field elements.

Field Elements

SE_Long_Float horizontal_width; (notes)
SE_Long_Float vertical_width; (notes)

Notes

Composed of Notes


Reference_Vector

 These are the lobe cross section axes.

 One component <Reference Vector> specifies the lobe axis
 direction with type = SE_REF_VEC_TYP_LIGHT_DIRECTION

 The other component <Reference Vector> specifies the vertical
 axis direction with type = SE_REF_VEC_TYP_VERTICAL_AXIS

Fields Notes


horizontal_width

 This defines the horizontal lobe width, measured in degrees,
 between 0 and 360 inclusive.

 This is measured perpendicular to the SE_REF_VEC_TYP_VERTICAL_AXIS
 <Reference Vector>.

vertical_width

 This defines the vertical lobe width, measured in degrees,
 between 0 and 360 inclusive.

 This is measured parallel to the SE_REF_VEC_TYP_VERTICAL_AXIS
 <Reference Vector>.
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Last updated: October 1, 2002 Copyright © 2002 SEDRIS™