Class

• <DRM Directional Light Behaviour>

Superclass

• <DRM Light Rendering Behaviour>

Subclass

• <DRM Blend Directional Light>
• <DRM Cone Directional Light>
• <DRM Pyramid Directional Light>

Definition

An instance of this DRM class specifies a directional light having a direction and lobe shape defined by a <DRM Lobe Data> component L. The lobe shape parameters are used by subclasses to specify shapes such as cones and pyramids.

The location of the light is specified by the <DRM Location> component. The direction at which the light is pointed is specified by the <DRM Reference Vector> component of L that has a vector_type field value of LIGHT_DIRECTION. The up axis of the light is specified by the <DRM Reference Vector> component of L that has a vector_type field value of VERTICAL_AXIS. The VERTICAL_AXIS vector specifies the rotational orientation of the light around the LIGHT_DIRECTION vector. These provide the necessary information to position the light in the currently applicable SRF, orient the light with respect to its VERTICAL_AXIS vector, and identify the direction in which the light is pointing. The lobe shape is centred horizontally and vertically around the LIGHT_DIRECTION vector, with origin at the location specified by the <DRM Location> component.

Directional lights can have both a primary and a secondary colour. These are specified by the <DRM Colour> components of the parent <DRM Geometry Representation> instance that have colour_mapping values of PRIMARY_LIGHT_RENDERING_BEHAVIOUR and SECONDARY_LIGHT_RENDERING_BEHAVIOUR, respectively.

Class diagram

Figure 6.63 — DRM_Directional_Light_Behaviour

Constraints

• Inheritance rule for <DRM Location>
• Publishable object

Example(s)

• See concrete subclasses for examples.