Class Name: Image Library

Superclass - <Library>

Subclasses

Definition

An instance of this DRM class specifies the complete list of unique <Image> instances resident within the transmittal.

Primary Page in DRM Diagram:

• 10

Secondary Pages in DRM Diagram:

• 1
• 22

Example

1. A <Image> instance in the <Image Library> instance can represent imagery intended to be texture-mapped to DRM objects in the transmittal.

   Consider an <Image Library> instance with an <Image> component that depicts a tree and a <Model> instance representing a tree, where the geometry of the <Model> instance consists of a single <Union Of Primitive Geometry> instance containing a single <Polygon> component P and having a <Stamp Behaviour> component as depicted in Figure 6.24.

   Here, the <Stamp Behaviour> instance allows P to be rotated at run-time so that the texture-mapped side always faces the observer.

   

   Figure 24 — <DRM Image Library> example

   Each <Vertex> component of P has a <Texture Coordinate> component that is used, together with the <Image Mapping Function> instance, to place the imagery on P.

2. A <Image> instance in the <Image Library> instance can represent imagery applied to a large number of polygons at once, where the <Polygon> instances are grouped under some <Aggregate Geometry> instance with an <Image Mapping Function> component.

   In this case, the <Image Mapping Function> instance determines the placement of the imagery within the currently scoped SRF. The imagery is then applied to the <Polygon> instances after they have been located within the specified SRF.

   This method has two common uses:

   1. the application of a geospecific image to many polygons in a seamless image, or

   2. the application of a single image to a large number of polygons within a <Model> instance (e.g., the image of an aircraft is wall-papered onto all the polygons within the <Model> instance representing that aircraft).

3. A <Image> instance in the <Image Library> instance can represent imagery to be transmitted that is not used by any <Image Mapping Function> instance. This imagery normally has anchor points, represented by an <Image Anchor> component of the <Image> instance.

FAQs

Can a transmittal contain <Image> instances that are not components of an <Image Library> instance?

No.

Is an <Image Library> instance permitted to have <Image> components that are not referenced through <Image Mapping Function> instances elsewhere in the transmittal?

Yes.

Constraints

• <<Publishable Object>>

Composed of (two-way)

• one or more {ordered} <Image> instances

Composed of (two-way metadata) (inherited)

• zero or one <Identification> instance

Component of (two-way)

• one <Transmittal Root> instance

Inherited Field Elements