Stamp Behaviour

The SEDRIS Data Representation Model APPENDIX A - Classes Stamp Behaviour

Class Name: Stamp Behaviour

Superclass - <SEDRIS Abstract Base>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

Indicates that the <Geometry Hierarchy> 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 x, y and/or z 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:

Secondary Pages in DRM Diagram:

This class appears on only one page of the DRM class diagram.

Example

A <Union Of Primitive Geometry>, containing a single textured <Polygon>, rotating freely about the z axis to represent a tree.
The <Union Of Primitive Geometry> would have a component <Stamp Behaviour>. x_axis_limits and y_axis_limits would be set to 0.0 for both clockwise and counter-clockwise limits. z_axis_limits would be set to SE_POSITIVE_INFINITY for clockwise and SE_NEGATIVE_INFINITY for counter-clockwise. The <Stamp Behaviour> would have a component <Location 3D> located at the base of the tree so that the z 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 Location 3D>?: 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.