Table 6.129 — DRM_Light_Source

Property

Description

Class
  • <DRM Light Source>

Superclass

Subclass

Definition

An instance of this DRM class specifies a source of light emission.

For a <DRM Light Source> instance that is a component of some <DRM Aggregate Geometry> instance(s), apply_to_children provides a mechanism for limiting the scope of the <DRM Light Source> instance. If apply_to_children is TRUE, only <DRM Primitive Geometry> instances in the component tree of those <DRM Aggregate Geometry> instances are affected by the <DRM Light Source> instance. If apply_to_children is FALSE, the <DRM Light Source> instance is not limited to the scope of those <DRM Aggregate Geometry> instances and thus applies globally.

For a <DRM Light Source> instance that is a component of some <DRM Aggregate Geometry> instance, override_positional_lights provides a mechanism to indicate with a value of TRUE that the effect of the <DRM Light Source> instance overrides that of any <DRM Base Positional Light> instances that would have otherwise applied to that <DRM Aggregate Geometry> instance.

EXAMPLE  This might be appropriate if the <DRM Light Source> instance is so close to the affected <DRM Geometry Representation> instance(s) that the effects of the <DRM Base Positional Light> instances would be negligible.

If override_positional_lights = FALSE, the effect of the <DRM Light Source> instance is combined with that of any <DRM Base Positional Light> instances that are already in effect.

For a <DRM Light Source> instance that is a component of some <DRM Aggregate Geometry> instance, override_infinite_lights provides a mechanism to indicate with a value of TRUE that the effect of the <DRM Light Source> instance overrides that of any <DRM Infinite Light> instances that would have otherwise applied to that <DRM Aggregate Geometry> instance. If override_infinite_lights = FALSE, the effect of the <DRM Light Source> instance is combined with that of any <DRM Infinite Light> instances that are already in effect.

A value of TRUE for the active_light_value field indicates that the light is on, while a value of FALSE indicates that the light is off. For a <DRM Light Source> instance with a <DRM Light Source Control Link> component X, the value of the active_light_value field is obtained from X.

Class diagram

Figure 6.154 — DRM_Light_Source

Inherited field elements

Field name

Range

Field data type

None

    

Field elements

Field name

Range

Field data type

apply_to_children

 

Boolean

override_positional_lights

 

Boolean

override_infinite_lights

 

Boolean

active_light_value

 

Boolean

Default field values

Default field values for DRM_Light_Source

Associated to (one-way) (inherited)
  • None.

Associated to (one-way)
  • None.

Associated by (one-way) (inherited)
  • None.

Associated by (one-way)
  • None.

Associated with (two-way) (inherited)
  • None.

Associated with (two-way)
  • None.

Composed of (two-way) (inherited)
  • None.

Composed of (two-way)

Composed of (two-way metadata) (inherited)
  • None.

Composed of (two-way metadata)
  • None.

Component of (two-way) (inherited)
  • None.

Component of (two-way)

Constraints

Clarifications

1A <DRM Classification Data> component, if present, allows a data provider to specify whether the <DRM Light Source> instance represents an environmental object, such as the sun.

2If a <DRM Light Source> instance is to be turned on and off dynamically, it has a <DRM Light Source Control Link> component to express that control mechanism.

Example(s)
  • See individual subclasses for examples.