Class

• <DRM Light Rendering Properties Control Link>

Superclass

• <DRM Control Link>

Subclass

• None.

Definition

An instance of this DRM class is a specialized <DRM Control Link> instance providing the connection between one or more <DRM Light Rendering Properties> instances and the <DRM Expression> instances that are used to determine whether the target <DRM Light Rendering Properties> instances are active and / or their candela_value field values.

The active_expression_index field specifies which component <DRM Expression>, if any, specifies the active_light_value of the target <DRM Light Rendering Properties> instances. If active_expression_index is zero (0), the active_light_value field values of the target instances are not controlled; otherwise, the value is a 1-based index into the ordered aggregation of <DRM Expression> instances.

The candela_value_expression_index field specifies which component <DRM Expression>, if any, specifies the candela_value of the target <DRM Light Rendering Properties> instances. If candela_value_expression_index is zero (0), the candela_value field values of the target instances are not controlled; otherwise, the value is a 1-based index into the ordered aggregation of <DRM Expression> instances.

The lower_candela_value_expression_index field specifies which component <DRM Expression>, if any, specifies the lower limit of the candela_value of the target <DRM Light Rendering Properties> instances. If lower_candela_value_expression_index is zero (0), no lower limit is specified; otherwise, the value is a 1-based index into the ordered aggregation of <DRM Expression> instances. Note that if candela_value_expression_index is zero, the candela_value field values of the target instances are not controlled, so this value would also be zero.

The upper_candela_value_expression_index field specifies which component <DRM Expression>, if any, specifies the upper limit of the candela_value of the target <DRM Light Rendering Properties> instances. If upper_candela_value_expression_index is zero (0), no upper limit is specified; otherwise, the value is a 1-based index into the ordered aggregation of <DRM Expression> instances. Note that if candela_value_expression_index is zero, the candela_value field values of the target instances are not controlled, so this value would also be zero.

Class diagram

Figure 6.150 — DRM_Light_Rendering_Properties_Control_Link

Constraints

• Publishable Object

Example(s)

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

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