Class Name: Ellipse

Superclass - Surface Geometry

Definition

A closed plane curve such that for each point on the curve, the sum of the point's distances from 2 fixed points (called the foci of the Ellipse) is a constant.

The major axis of the Ellipse is the line passing through the foci of the Ellipse. The minor axis of the Ellipse is the line perpendicular to the major axis that passes through the center of the Ellipse. The component Location 3D locates the center.

The first component Reference Vector (vector_type = SE_MAJOR_AXIS) gives the direction of the major axis. The second component Reference Vector (vector_type = SE_FACE_NORMAL) defines the normal direction to the plane of the Ellipse, and must be perpendicular to the major axis Reference Vector.

Primary Page in DRM Diagram:

• 5

Secondary Pages in DRM Diagram:

• 13

Example

1. The physical extent of certain underwater acoustic phenomena are best described by oval surface geometries in some cases (and by Elliptic Cylinder Volume Geometries in others.

FAQs

Why doesn't SEDRIS have a Circle class?

Because a circle is a special case of an Ellipse for which the major and minor axes have the same length.

Constraints

• No Attribute Conflicts
• Non Crossing Aggregations
• Non Cyclic Aggregations
• Precedence of Attribute Set Index
• Color Mapping Restrictions
• Image Mapping Functions and Texture Coordinates
• Nested Primitive Geometry
• Non Nestable Continuous LOD

Composed of (one-way)(inherited)

• optionally, some {ordered} Attribute Set Indices
• optionally, a Classification Data
• optionally, some Property Tables
• optionally, some Property Table References
• optionally, some Property Values
• optionally, some Tack Points
• optionally, some {ordered} Colors
• optionally, a Light Rendering Properties
• optionally, a Rendering Properties
• optionally, some {ordered} Image Mapping Functions
• optionally, a Rendering Priority Level

Composed of (one-way)

• one Location (notes)
• exactly (2) {ordered} Reference Vectors

Composed of (two-way)(inherited)

• optionally, a Union of Primitive Geometry

Composed of (two-way)

• optionally, a Geometry Node (notes)

Composed of (one-way metadata)(inherited)

• optionally, a Time Constraints Data

Component of (two-way)(inherited)

• one or more Union of Primitive Geometries

Field Elements

Notes

Composed of Notes

Geometry_Node

 (corresponds to center)

Location

 of center

Fields Notes

major_axis_length

 in meters > 0.0

minor_axis_length

 in meters > 0.0