Class Name: Light Rendering Properties Control Link

Superclass - Control Link

Definition

A Control Link providing the connection between the Light Rendering Properties class and the Expressions that are used to determine whether it is active and and the value of its candela_value field.

The active_expr_index, candela_value_expr_index, lower_candela_value_index, and upper_candela_value_index are 1-based indices into the ordered aggregation of Expressions, and are used to select the specific Expressions that define the Light Rendering Properties's active_light_value and candela_value fields.

Primary Page in DRM Diagram:

• 17

Secondary Pages in DRM Diagram:

• 3

Example

1. Consider a flight simulator database containing an area of terrain representing a city as seen from the air. Some of the Polygons of this terrain have Light Rendering Properties with Twinkling Light Behavior, representing city lights. These Light Rendering Properties share a Light Rendering Properties Control Link that turns them on and off depending on the time of day (on at dusk, off at dawn).

2. Consider a runway, bordered on either side by a Line representing the runway lights. Each Line has a Light Rendering Properties with Strobing Light Behavior, and a Light Rendering Properties Control Link that turns the lights on and off depending on the time of day (on at dusk, off at dawn).

FAQs

What does a Light Rendering Properties Control Link control?

A Light Rendering Properties Control Link controls whether the associated Light Rendering Properties are on or off, and the candela_value of the Light Rendering Properties.

Can I use a Light Rendering Properties Control Link to change the Light Rendering Behavior of the Light Rendering Properties?

No. The links to the Light Rendering Behaviors are associations within the transmittal, and associations cannot be changed dynamically.

Constraints

Composed of (two-way)(inherited)

• one or more {ordered} Expressions

Component of (two-way)

• one or more Light Rendering Properties

Inherited Field Elements

Field Elements

Notes

Fields Notes

description

 A text description of what the Control_Link is for

active_expr_index

 index of the expression whose value controls whether a set of
 <Light Rendering Properties> are on or off.  If the expression
 evaluates to SE_TRUE, then they are on.

candela_value_expr_index

 index of the expression whose value controls the candela_value
 of the affected <Light Rendering Properties> object.

lower_candela_value_index

 index of the expression defining the lower limit of the
 candela_value. A lower_candela_value_index value of 0
 means no lower limit was defined.

upper_candela_value_index

 index of the expression defining the upper limit of the
 candela_value. An upper_candela_value_index value of 0
 means no upper limit was defined.