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 of a light source or directional light in terms of direction vectors for the central axis ( SE_REF_VEC_TYP_LIGHT_DIRECTION), the SE_REF_VEC_TYP_VERTICAL_AXIS, and horizontal and vertical angular widths.

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_REF_VEC_TYP_LIGHT_DIRECTION and SE_REF_VEC_TYP_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_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 vector_type = SE_REF_VEC_TYP_LIGHT_DIRECTION.

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

Fields Notes


horizontal_width

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

vertical_width

 The vertical_width field specifies the vertical lobe width,
 measured in radians parallel to the SE_REF_VEC_TYP_VERTICAL_AXIS
 <Reference Vector> component.
Prev: Literal. Next: Local 4x4. Up:Index.

Last updated: July 16, 2004 Copyright © 2004 SEDRIS™