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 specifies a cone or a pyramid shape, termed the lobe of the light, of a light source or directional light in terms of direction vectors for the central axis of the light (SE_REFVEC_LIGHT_DIRECTION), the SE_REFVEC_VERTICAL_AXIS, and horizontal and vertical angular widths. Both reference vectors are specified relative to the SRF of the light source or directional light for which the <Lobe Data> instance is a component. The component SE_REFVEC_LIGHT_DIRECTION vector and SE_REFVEC_VERTICAL_AXIS vector shall not be parallel.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

This class appears on only one page of the DRM class 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 SE_REFVEC_LIGHT_DIRECTION and SE_REFVEC_VERTICAL_AXIS, how is the horizontal axis specified?

The horizontal direction is always perpendicular to the plane of the two <Reference Vector> instances of type SE_REFVEC_LIGHT_DIRECTION and SE_REFVEC_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; 2
SE_Long_Float vertical_width; 3

Notes

Composed of Notes


Reference_Vector

These two <Reference Vector> components specify the lobe cross section axes. One <Reference Vector> component specifies the central axis of the lobe with vector_type = SE_REFVEC_LIGHT_DIRECTION. The other <Reference Vector> component specifies the vertical axis direction with vector_type = SE_REFVEC_VERTICAL_AXIS.

Fields Notes

horizontal_width

The horizontal_width field specifies the horizontal lobe width, in radians, measured perpendicular to the SE_REFVEC_VERTICAL_AXIS <Reference Vector> component.

vertical_width

The vertical_width field specifies the vertical lobe width, in radians, measured parallel to the SE_REFVEC_VERTICAL_AXIS <Reference Vector> component.

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Last updated: July 26, 2006 Copyright © 2006 SEDRIS™