Class Name: Stamp Behaviour

Superclass - <SEDRIS Abstract Base>

Subclasses

Definition

An instance of this DRM class specifies that the <Geometry Hierarchy> instance of which the <Stamp Behaviour> is a component rotates automatically with respect to the viewer's location, attempting to continually face the viewer.

The <Geometry Hierarchy> rotates about the u, v and / or w axes, within the specified angular limits. The centre of rotation is specified by the component <Location 3D>. The axes are positioned at the centre of rotation, aligned with the equivalent spatial reference frame axes. Geometry with <Stamp Behaviour> is normally planar in nature and is considered to "face" along the normal of that plane.

If an axis' clockwise limit is set to SE_POSITIVE_INFINITY and its counter-clockwise limit is set to SE_NEGATIVE_INFINITY, then the aggregating <Geometry Hierarchy> can rotate freely about that axis. If all axis limits are set in this way, then the <Geometry Hierarchy> will rotate freely in any direction about the centre of rotation.

Primary Page in DRM Diagram:

• 3

Secondary Pages in DRM Diagram:

• 4
• 7

Example

1. Consider a <Union Of Primitive Geometry> instance, containing a single textured <Polygon> instance, rotating freely about the w axis to represent a tree.

   The <Union Of Primitive Geometry> instance in this example has a <Stamp Behaviour> component, with u_axis_limits and v_axis_limits set to 0.0 for both the clockwise and counter-clockwise limits, and w_axis_limits set to SE_POSITIVE_INFINITY for clockwise and SE_NEGATIVE_INFINITY for counter-clockwise. The <Stamp Behaviour> instance has a component <Location 3D> instance located at the base of the tree, so that the w axis runs up the centre of the tree.

FAQs

Since <Stamp Behaviour> instances shall be specified in a 3D LSR spatial reference frame, why is the centre of rotation a <Location 3D> rather than an <LSR 3D Location>?

Because if and when a <Stamp Behaviour>'s native LSR SRF is instanced into a non-LSR SRF, the <Location 3D> shall be specified so that it can be transformed into the target SRF.

Constraints

• <<Publishable Object>>

Composed of (two-way)

• one <Location 3D> instance (notes)

Component of (two-way)

• zero or more <Aggregate Geometry> instances
• zero or more <Geometry Model Instance> instances

Inherited Field Elements

Field Elements

Notes

Composed of Notes

Location_3D

 This is the centre of rotation.

Fields Notes

u_axis_limits

 The u_axis_limits field specifies the angular limits.

v_axis_limits

 The v_axis_limits field specifies the angular limits.

w_axis_limits

 The w_axis_limits field specifies the angular limits.