Table 6.158—DRM_Light_Source

Property

Description

Superclass

·         <DRM SEDRIS Abstract Base>

Class

·         <DRM Light Source>

Subclass

·         <DRM Infinite Light>

·         <DRM Positional Light>

Definition

This is an abstract DRM class that specifies a source of light emission that illuminates only the <DRM Geometry> that appears in the section of the hierarchy beneath the object to which the <DRM Light Source> is attached.

A <DRM Light Source> shall specify three colours (Ambient, Diffuse, Specular).

An optional <DRM Control Link> can also be used to allow the light source to be turned on or off.

Example(s)

·         A light bulb.

·         The Sun.

·         A candle.

Inherited field elements

field_name

range

Field_Data_Type

none

 

 

Field elements

field_name

range

Field_Data_Type

apply_to_children1

 

Boolean

override_positional_lights2

 

Boolean

override_infinite_lights3

 

Boolean

active_light_value4

 

Boolean

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)

·         one<DRM Ambient Colour>

·         one <DRM Diffuse Colour>

·         zero or one <DRM Light Source Control Link>

·         one <DRM Specular Colour>

Composed of (two-way metadata) (inherited)

·         none

Composed of (two-way metadata)

·         none

Component of (two-way) (inherited)

·         none

Component of (two-way)

·         one or more <DRM Aggregate Geometry>s

Constraints

·         none

Notes

1 Flag to allow lights to limit their scope to only affecting their children. If apply_to_children is FALSE, the light is assumed to apply globally.

2 Flag to reset the current cumulative definition of local  <DRM Light Source>s. If override_positional_lights is TRUE, all <DRM Positional Light> sources in the current scope are cleared.

3 Flag to reset the current cumulative definition of <DRM Infinite Light> sources. If override_infinite_lights is TRUE, all <DRM Infinite Light> sources in the current scope are cleared.

4 A value of TRUE indicates the light is on while a value of FALSE indicates the light is off. This is the default/active state of the light.

Class diagram

<DRM Light Source>