Class

• <DRM World 3x3>

Superclass

• <DRM SEDRIS Abstract Base>

Subclass

• None.

Definition

An instance of this DRM class specifies a nine-element matrix containing scaling and rotation data as part of a <DRM World Transformation> instance. The direction of rotation is determined by the right-hand rule.

Translation data is not provided by a <DRM World 3x3> instance, because a <DRM World 3x3> instance only exists as a component of a <DRM World Transformation> instance. The translation component of a <DRM World Transformation> instance is provided by the mandatory <DRM Location> component of the <DRM World Transformation> instance. The <DRM World Transformation> instance is applied as specified in 4.7.6 Representing models within an environment.

<DRM World Transformation> instances usually exist in the scope of a <DRM Environment Root> instance defining a non-LSR SRF. Consequently, <DRM World 3x3> instances usually exist within a ’world’ SRF, hence the name.

The matrix multiplication order is defined by w = M × v, where M is the matrix of the <DRM World 3x3> instance, v is the original location column vector, and w is the resulting location column vector.

The world_3x3 field specifies a non-singular rotation and scale matrix.

Class diagram

Figure 6.380 — DRM_World_3x3

Constraints

• Publishable object

Example(s)

• A <DRM World 3x3> instance specifies the scale and rotation applied to a <DRM Model> instance when placing an instance.

• Consider a model of a house. A <DRM World 3x3> instance is used as part of a <DRM World Transformation> instance that rotates the instantiation of the house on Bourbon Street to face east. Another <DRM World 3x3> instance is used as part of a <DRM World Transformation> instance that scales another instance of the house model larger and rotates it to face west on the other side of the street.

• See the <DRM Local 4x4> class for more examples and explanations of matrix structure.