Topo-Feature

Demonstration of a transform from CityJSON to TopoFeature

A datatype for referencing a topological object with an orientation indicator ('+' or '-'), used to define the sense (direction/orientation) of boundary elements such as edges in rings or faces in shells.

Demonstration of a schema using coordinates of points, withpout duplication

This building block defines a GeoJSON feature with topological relationships to point nodes, or other to TopoFeatures. Testing and visualisation of its examples draw on a common set of referenced objects (points, edges, faces) shared across the topo-* building blocks, at `_sources/examples/referenced-objects.ttl`.

Defines options for describing Arcs, Circles, Splines using point features as canonical source of geometry coordinates. Testing and visualisation of its examples draw on a common set of referenced objects (points, edges, faces) shared across the topo-* building blocks, at `_sources/examples/referenced-objects.ttl`.

This building block defines a GeoJSON (or FG-JSON) Feature Collection for a set of features with geometries defined by topological relationships. From these it is possible to derive simplified geometries using coordinates for each feature.

Demonstration of a schema using coordinates of points, without duplication. Reuses context but constrains to Line types. Testing and visualisation of its examples draw on a common set of referenced objects (points, edges, faces) shared across the topo-* building blocks, at `_sources/examples/referenced-objects.ttl`.

A feature representing a Ring in topology: an ordered, closed sequence of oriented Edge references that form a boundary loop. A Ring is used as the boundary of a Face.

A feature representing a Face in topology: a bounded planar region described by an outer boundary Ring and zero or more inner boundary (hole) Rings. Faces are used as the surfaces of a Shell/Solid.

Typical 3D polyhedrons using features with Point geometry coordinates - note this does not support full topology of shared faces but matches many simplified geometry models.

A feature representing a Shell in topology: a closed set of oriented Face references forming the boundary surface of a Solid. A Shell is the 3D analog of a Ring — it bounds a volumetric region.

A feature representing a Solid in topology: a volumetric region bounded by one or more oriented Shell references. The first Shell is the outer boundary; any additional Shells describe interior voids. A Solid is the 3D analog of a Face — it is bounded by Shells the way a Face is bounded by Rings.

A schema for a structured topology dataset containing typed Feature Collections for each topological dimension: points, edges (Line features), rings (Ring features), faces (Face features), shells (Shell features), and solids (Solid features). Each collection is restricted to its specific building block type, enabling referential integrity across the topology hierarchy. Testing and visualisation of its examples draw on a common set of referenced objects (points, edges, faces) shared across the topo-* building blocks, at `_sources/examples/referenced-objects.ttl`.