Class Name: Property Set Table Group

Superclass - <SEDRIS Abstract Base>

Subclasses

Definition

An instance of this DRM class specifies an interchangeable group of one or more <Property Set Table> instances. The primary <Property Set Table> component of the group is indicated by the primary_table_index. When a reference is made to a <Property Set Table> instance (for example, from a <Property Set Index> component of a <Polygon> instance), the reference identifies the <Property Set Table Group> instance and the index within the <Property Set Table> instance, but not the specific <Property Set Table> component of the <Property Set Table Group> instance. By definition, a <Property Set Index> instance refers to a <Property Set> component of the primary <Property Set Table> component of the indicated <Property Set Table Group> instance. An alternate <Property Set Table> instance from within the <Property Set Table Group> instance can be chosen at the discretion of the data consumer.

Primary Page in DRM Diagram:

• 19

Secondary Pages in DRM Diagram:

• 10

Example

1. Consider a transmittal containing a <Property Set Table Library> instance with only one <Property Set Table Group> component, which in turn has only one <Property Set Table> component. That <Property Set Table> instance is the one and only <Property Set Table> instance for the entire transmittal.

2. A <Property Set Table Group> instance contains two <Property Set Table> components: one for normal, OTW viewing and the other to change the appearance of the view to be a view as seen through night vision goggles.

3. A <Property Set Table Group> instance contains three <Property Set Table> components with the same usage of OTW. One <Property Set Table> instance defines the colours and textures as originally created by the data modellers. The second <Property Set Table> instance has different shades of blue for the lakes and skies because a company executive came through and did not like the blues that were there. The third <Property Set Table> instance contains yet another set of blues for the lakes, different textures for the lakes and different shades of green for the trees and tanks, because the customer in charge of the program came through and did not think the colours and textures were realistic.

FAQs

Can a transmittal in any way refer to a <Property Set Table> component of a <Property Set Table Group> instance other than the primary <Property Set Table> component?

No. The only <Property Set Table> component that can be referenced in any <Property Set Table Group> instance is the primary <Property Set Table> component.

Since they cannot be referenced in a transmittal, why bother to have alternate <Property Set Table> components within a <Property Set Table Group> instance?

Because in real life, many run-time systems have multiple colour and material tables they can switch between for various reasons, and these tables should be shared to promote interoperability. See the example section, below.

Constraints

• <<Publishable Object>>
• <<Property Set Table Size>>

Associated by (one-way)

• zero or more <Property Set Index> instances

Composed of (two-way)

• one or more {ordered} <Property Set Table> instances

Composed of (two-way metadata)

• zero or one <Access> instance
• zero or one <Citation> instance
• zero or more <Cross Reference> instances
• zero or one <Description> instance

Component of (two-way)

• one <Property Set Table Library> instance

Inherited Field Elements

Field Elements

Notes

Fields Notes

primary_table_index

The primary_table_index specifies the primary <Property Set Table> component from the ordered <Property Set Table> components of the <Property Set Table Group> instance.

table_size

The table_size field specifies the size of each <Property Set Table> component of the <Property Set Table Group> instance.