Class Name: Property Set

Superclass - <SEDRIS Abstract Base>

Subclasses

Definition

An instance of this DRM class groups together a set of instances of classes that have formal component relationships with the <Geometry Representation> class and/or the <Feature Representation> class and specify either properties, such as <Rendering Priority Level> instances, or metadata.

A <Property Set> instance provides a mechanism for a set of properties to be explicitly reused by many <Geometry Representation> instances and/or <Feature Representation> instances. A <Property Set> instance may contain property objects used by <Geometry Representation> instances and/or <Feature Representation> instances. If it contains property objects that are used by <Geometry Representation> instances and is referenced by a <Feature Representation> instance, the <Geometry Representation>-related property objects are ignored. The reverse is also true.

Primary Page in DRM Diagram:

• 19

Secondary Pages in DRM Diagram:

• 6

Example

1. A number of <Polygon> instances that are all coloured red and rendered using flat shading each have the same <Property Set Index> component that references a <Property Set> instance containing a <Colour> component specifying red and a <Rendering Properties> component specifying flat shading.

2. Consider a number of <Polygon> instances that are all coloured green, have grass texture that is modulated, and have an EAC_SURFACE_MATERIAL_TYPE specifying EEC_SRF_MATTY_GRASS. A common <Property Set Index> instance specifies a <Property Set> instance containing:

   1. a <Colour> instance specifying green,
   2. an <Image Mapping Function> instance specifying image_mapping_method = SE_IMAGMAPMETH_MODULATE, and
   3. a <Property Value> instance specifying an EAC_SURFACE_MATERIAL_TYPE value of EEC_SRF_MATTY_GRASS.

3. Consider a number of <Polygon> instances that all have the same electromagnetic properties and are coloured grey. A common <Property Set> instance contains a <Colour> component specifying grey and a <Property Table Reference> component into a <Property Table> instance of electromagnetic properties.

4. Consider a <Feature Representation> instance that is associated with a <Geometry Representation> instance that has been developed from it. Both reference the same <Property Set> instance, which contains a <Colour> component, an <Image Mapping Function> component, and a <Browse Media> component. The <Geometry Representation> instance uses the <Colour> component and <Image Mapping Function> component but ignores the <Browse Media> component.

5. Consider a <Feature Representation> instance with a <Data Quality> component, the fictional field of which is set to SE_TRUE. This particular <Feature Representation> instance also has a <Property Set Index> component, referencing a <Property Set> instance having a <Data Quality> component, the fictional field of which is set to SE_FALSE. Since a <Feature Representation> instance may have at most one <Data Quality> component, the <Data Quality> instance with fictional set to SE_TRUE is used, as it is contained directly by the <Feature Representation> instance.

6. Consider a <Geometry Representation> instance with two <Property Table Reference> components, that references a <Property Set> instance that contains another three <Property Table Reference> components where all five have distinct meanings. As a <Geometry Representation> instance may contain many <Property Table Reference> components, all five are used by the <Geometry Representation> instance as required. The two that are contained directly are used first, then the three that are contained in the <Property Set> instance.

7. A <Union Of Primitive Geometry> instance contains two <Property Table Reference> components and references two <Property Set> instances. The first <Property Set> instance contains another <Property Table Reference> component and the second <Property Set> instance contains another three <Property Table Reference> components. As an <Aggregate Geometry> instance may contain many <Property Table Reference> components, all six are used by the <Union Of Primitive Geometry> instance as required. The two that are contained directly are used first, then the one that is contained in the first <Property Set> instance, and finally the three that are contained in the second <Property Set> instance.

FAQs

Where can users find more information on property objects?

See P4V9 of the SEDRIS Documentation Set for further information.

What is the order of precedence for components of a single <Property Set> instance?

See <<Precedence of Property Set Index>>.

What if a <Geometry Representation> instance or <Feature Representation> instance has more than one <Property Set Index> component, where the referenced <Property Set> instances have conflicting components?

See <<Precedence of Property Set Index>>.

Constraints

• <<Publishable Object>>
• <<Presentation Domain Constraints>>
• <<Property Constraints>>

Composed of (two-way)

• zero or one <Classification Data> instance
• zero or more <Colour> instances
• zero or more {ordered} <Image Mapping Function> instances
• zero or one <Light Rendering Properties> instance
• zero or one <Presentation Domain> instance
• zero or more <Property Table> instances
• zero or more <Property Table Reference> instances
• zero or more <Property Value> instances
• zero or one <Rendering Priority Level> instance
• zero or one <Rendering Properties> instance

Composed of (two-way metadata)

• zero or one <Data Quality> instance
• zero or one <Identification> instance
• zero or one <Time Constraints Data> instance

Component of (two-way)

• one <Property Set Table> instance

Inherited Field Elements