ISO/IEC 18023-1:200x(E) — Table 6.247 DRM_Spatial_Index_Related

Table 6.247 — 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 component <DRM Geometry Hierarchy> 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> indicates the tile that it represents.

Class diagram

Figure 6.294 — DRM_Spatial_Index_Related_Geometry

Inherited field elements

Field name	Range	Field data type
unique_descendants ¹		Boolean
strict_organizing_principle ²		Boolean

Field elements

Field name	Range	Field data type
sparse ³		Boolean
column_count		Integer_Positive
row_count		Integer_Positive
column_width ⁴		Long_Float
row_width ⁵		Long_Float
spacing_unit		Spatial_Index_Spacing_Unit

Associated to (one-way) (inherited)

None.

Associated to (one-way)

None.

Associated by (one-way) (inherited)

zero or one <DRM Hierarchy Summary Item> instance⁶
zero or more <DRM Reference Surface> instances⁷

Associated by (one-way)

None.

Associated with (two-way) (inherited)

zero or more <DRM Feature> instances⁸
zero or more <DRM Geometry Hierarchy> instances⁹

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 Level Of Detail Data> instances
zero or one <DRM Bounding Volume> instance
zero or more <DRM Camera Point> instances
zero or more <DRM Collision Volume> instances¹⁰
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> instance¹¹

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 Level Of Detail Related Geometry> instances, each with a <DRM Base Level Of Detail 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

Clarifications

¹ If this value is TRUE, each “descendant” of this aggregation - that is, each <DRM Geometry> instance that exists in the component tree rooted at the given <DRM Aggregate Geometry> - shall be unique, in the sense that it shall appear in only one “branch” of this aggregation. If unique_descendants is FALSE, at least one <DRM Geometry> instance appears in more than one “branch” of the aggregation.

² If this value is TRUE, each “branch” of this aggregation strictly complies with the organizing principle for its particular subclass. If this value is FALSE, at least one “branch” does not strictly comply with the given organizing principle. See the organizing principle constraint for each specific subclass for details.

³ If this value is FALSE, all column and row entries are present; otherwise one or more entries are not present.

⁴ This is the length of a cell in the given unit along the X axis.

⁵ This is the length of a cell in the given unit along the Y axis.

⁶ An association between a <DRM Geometry Hierarchy> instance and a <DRM Feature> instance indicates that the <DRM Geometry Hierarchy> and the <DRM Feature> are alternate representations of the same environmental object.

⁷ An association between two <DRM Geometry Hierarchy> instances indicates that they are alternate representations of the same environmental object.

⁸ An association from a <DRM Hierarchy Summary Item> instance to a <DRM Geometry Hierarchy> indicates that the <DRM Hierarchy Summary Item> summarizes that <DRM Geometry Hierarchy>.

⁹ An association from a <DRM Reference Surface> instance to a <DRM Geometry Hierarchy> indicates that the <DRM Geometry Hierarchy> organizes the geometric objects that specify the resolution surface of the <DRM Reference Surface>.

¹⁰ In the case where multiple <DRM Collision Volume> components are specified for a given <DRM Aggregate Geometry>, the union of the volumes thus specified is used in collision detection.

¹¹ This is the origin of the collection, which is the lower-left corner.

Example(s)

See Spatial index related organizing principle, example #1.
Consider an <DRM Environment Root> describing a terrain surface that is a mix of grids and polygons, organized by spatial indexing into 9 cells.

A B C

D E F

G H I

All cells except H are grids (represented in SEDRIS as <DRM Property Grid> instances) captured at 1 level of detail. Cell H consists of <DRM Polygon> instances.

Figure 6.295 — <DRM Spatial Index Related Geometry> example

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