ISO/IEC 18023-1:200x(E) — Table 6.252 DRM_Spatial_Index_Related

Table 6.252 — DRM_Spatial_Index_Related_Geometry

Property

Description

Class

<DRM Spatial Index Related Geometry>

Superclass

<DRM Aggregate Geometry>

Subclass

None.

Definition

An instance of this DRM class specifies an aggregation of <DRM Geometry Hierarchy> objects in which each <DRM Geometry Hierarchy> component represents a different tile within a spatially indexed (tiled) organization of <DRM Primitive Geometry> objects within a SEDRIS transmittal. The <DRM Spatial Index Data> link object attached to each component <DRM Geometry Hierarchy> instance indicates the tile that it represents.

If the value of the sparse field is FALSE, all column and row entries are present; otherwise one or more entries are not present.

The column_count field specifies the number of cells along the X axis.

The row_count field specifies the number of cells along the Y axis.

The column_width field specifies the length of a cell in the given unit along the X axis.

The row_width field specifies the length of a cell in the given unit along the Y axis.

The spacing_unit field specifies the unit of measurement used for the spacing of the spatial index.

Clarifications

¹ An association between a <DRM Feature Representation> instance and a <DRM Geometry Hierarchy> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <DRM Base Association Data> instance on the association relationship.

² An association between two <DRM Geometry Hierarchy> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <DRM Base Association Data> instance on the association relationship.

³ An association between a <DRM Feature Representation> instance and a <DRM Geometry Hierarchy> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <DRM Base Association Data> instance on the association relationship.

⁴ An association between two <DRM Geometry Hierarchy> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <DRM Base Association Data> instance on the association relationship.

⁵ An association from a <DRM Hierarchy Summary Item> instance to a <DRM Geometry Hierarchy> instance indicates that the <DRM Hierarchy Summary Item> instance summarizes that <DRM Geometry Hierarchy> instance.

⁶ An association from a <DRM Reference Surface> instance to a <DRM Geometry Hierarchy> instance indicates that the <DRM Geometry Hierarchy> instance organizes the geometric objects that specify the resolution surface of the <DRM Reference Surface> instance.

⁷ In the case where multiple <DRM Collision Volume> components are specified for a given <DRM Aggregate Geometry> instance, the union of the volumes thus specified is used in collision detection.

⁸ This is the origin of the collection, which is the lower-left corner.

Class diagram

Figure 6.299 — DRM_Spatial_Index_Related_Geometry

Inherited field elements

Field name	Range	Field data type
unique_descendants		Boolean
strict_organizing_principle		Boolean

Field elements

Field name	Range	Field data type
sparse		Boolean
column_count		Integer_Positive
row_count		Integer_Positive
column_width		Long_Float
row_width		Long_Float
spacing_unit		Spatial_Index_Spacing_Unit

Associated to (one-way) (inherited)

zero or more <DRM Feature Representation> instances, each with a <DRM Base Association Data> link object¹
zero or more <DRM Geometry Hierarchy> instances, each with a <DRM Base Association Data> link object²

Associated to (one-way)

None.

Associated by (one-way) (inherited)

zero or more <DRM Feature Representation> instances, each with a <DRM Base Association Data> link object³
zero or more <DRM Geometry Hierarchy> instances, each with a <DRM Base Association Data> link object⁴
zero or one <DRM Hierarchy Summary Item> instance⁵
zero or more <DRM Reference Surface> instances⁶

Associated by (one-way)

None.

Associated with (two-way) (inherited)

None.

Associated with (two-way)

None.

Composed of (two-way) (inherited)

zero or one <DRM Classification Data> instance
zero or more {ordered} <DRM Property Set Index> instances
zero or more <DRM Property Table> instances
zero or more <DRM Property Table Reference> instances
zero or more <DRM Property Value> instances
zero or one <DRM Reference Surface> instance
zero or more <DRM Sound Instance> instances
zero or more <DRM Base LOD Data> instances
zero or one <DRM Bounding Volume> instance
zero or more <DRM Camera Point> instances
zero or more <DRM Collision Volume> instances⁷
zero or more <DRM Colour> instances
zero or one <DRM Conformal Behaviour> instance
a bounded set of 0..3 <DRM Geometric Centre> instances
zero or more <DRM Geometry Topology Hierarchy> instances
zero or more {ordered} <DRM Image Mapping Function> instances
zero or one <DRM Light Rendering Properties> instance
zero or more <DRM Light Source> instances
zero or one <DRM LSR Transformation> instance
zero or one <DRM Overload Priority Index> instance
zero or one <DRM Perimeter Data> instance
zero or one <DRM Presentation Domain> instance
zero or more <DRM Property Description> instances
zero or one <DRM Rendering Priority Level> instance
zero or one <DRM Rendering Properties> instance
zero or one <DRM Spatial Extent> instance
zero or one <DRM Stamp Behaviour> instance

Composed of (two-way)

one or more <DRM Geometry Hierarchy> instances, each with a <DRM Spatial Index Data> link object
one <DRM Location> instance⁸

Composed of (two-way metadata) (inherited)

zero or one <DRM Time Constraints Data> instance
zero or one <DRM Access> instance
zero or more <DRM Cross Reference> instances
zero or one <DRM Data Quality> instance
zero or one <DRM Description> instance

Composed of (two-way metadata)

None.

Component of (two-way) (inherited)

zero or more <DRM Alternate Hierarchy Related Geometry> instances, each with a <DRM Hierarchy Data> link object
zero or more <DRM Animation Related Geometry> instances
zero or more <DRM Classification Related Geometry> instances, each with a <DRM Classification Data> link object
zero or one <DRM Environment Root> instance
zero or one <DRM Geometry Model> instance
zero or more <DRM LOD Related Geometry> instances, each with a <DRM Base LOD Data> link object
zero or more <DRM Octant Related Geometry> instances, each with a <DRM Octant Data> link object
zero or more <DRM Perimeter Related Geometry> instances, each with a <DRM Perimeter Data> link object
zero or more <DRM Quadrant Related Geometry> instances, each with a <DRM Quadrant Data> link object
zero or more <DRM Separating Plane Relations> instances, each with a <DRM Separating Plane Data> link object
zero or more <DRM Spatial Index Related Geometry> instances, each with a <DRM Spatial Index Data> link object
zero or more <DRM State Related Geometry> instances, each with a <DRM State Data> link object
zero or more <DRM Time Related Geometry> instances, each with a <DRM Time Constraints Data> link object
zero or more <DRM Union Of Geometry Hierarchy> instances

Component of (two-way)

None.

Constraints

Example(s)

Consider a <DRM Environment Root> instance describing a terrain surface that is a mix of grids and polygons, organized by spatial indexing into nine cells.

A B C

D E F

G H I

All cells except H are grids (represented in the DRM as <DRM Property Grid> instances) captured at one level of detail. Cell H consists of <DRM Polygon> instances.

Figure 6.300 — <DRM Spatial Index Related Geometry> example

The components of the <DRM Spatial Index Related Geometry> instance are not ordered; the <DRM Spatial Index Data> instance is used to identify the individual tiles.