The SEDRIS Data Representation Model
APPENDIX A - Classes
Geometry Volume

Class Name: Geometry Volume

Superclass - <Geometry Topology>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class is a three-dimensional <Geometry Topology> instance used to represent an enclosed region of space that is bounded by four or more <Geometry Face> instances.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

  1. Consider a <Polyhedron> instance representing a building. It has:

    1. a collection of <Polygon> instances that define its geometric shape;
    2. an associated <Geometry Volume> instance that defines its topological relationships;
    3. a <Classification Data> component that classifies it as an ECC_BUILDING;
    4. <Property Value> components that describe its characteristics, such as material composition, and
    5. a <Label> instance that identifies it as "The Empire State Building".

FAQs

When are <Geometry Volume> instances required?

<Geometry Volume> instances are required only when the geometry topology level is five.

Are there any geometric constraints on <Geometry Volume> instances?

Yes. <Geometry Volume> instances must always have closed external boundaries (defined by their <Polygon> components), and their interiors must be fully connected. At geometry topology level 5, the interiors of <Geometry Volume> instances may not intersect or overlap one another, and <Geometry Volume> instances may meet only along one or more common <Geometry Face> instances.

Can <Geometry Volume> instances exist at any geometry topology level?

Yes. <Geometry Volume> instances may exist at any geometry topology level. At geometry topology level 5, the collection of <Geometry Volume> instances must exhaustively and exclusively partition the 3D topological space, such that exactly two <Geometry Volume> instances shall be bounded by each <Geometry Face> instance.

Constraints

Associated with (two-way)

Component of (two-way) (inherited)

Inherited Field Elements

This class has no inherited field elements.

Notes

Associated with Notes


Geometry_Edge

If a <Geometry Volume> instance has an association relationship with a <Geometry Edge> instance, that <Geometry Edge> instance is contained within the <Geometry Volume> instance.


Geometry_Face

The <Geometry Face> instances that border a <Geometry Volume> instance indicate the relationship by their association to the <Geometry Volume> instance. The converse of this relationship is the association relationship between the <Geometry Volume> class and the <Geometry Face> class.


Geometry_Node

If a <Geometry Volume> instance has an association relationship with a <Geometry Node> instance, that <Geometry Node> instance is contained within the <Geometry Volume> instance.

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Last updated: July 26, 2006 Copyright © 2006 SEDRIS™