Fixture

Definition

A Fixture models the presence and approximate physical extent of a moveable or semi-permanent physical asset possessing any of the following characteristics:

  • An asset that, if removed, does not impact the structural integrity of the physical building or outdoor level.
  • An asset that has utility within the defined space and serves to support a service/business function.
  • An asset that serves a decorative function, may have limited or no utility from a service/business standpoint, but enhances the pedestrian "experience."

Feature Structure

  • Fixture objects are Feature objects
  • Fixture objects MUST have an "id" member with a FEATURE-ID value
  • Fixture objects MUST have a "feature_type" member with the value "fixture"
  • Fixture objects MUST have a "geometry" member with a POLYGONAL value

Property Keys

Property Type Description
category FIXTURE-CATEGORY The category that best describes the function of the physical Fixture.
name null or LABELS The name of the Fixture as declared by the Venue Organization.
alt_name null or LABELS Alternative name for the Fixture that may be recognized by the Venue Organization.
anchor_id null or ANCHOR-ID ID reference to Anchor record.
level_id LEVEL-ID Unique identifier of the Level feature the Fixture possesses a spatial relationship with.
display_point null or DISPLAY-POINT The curated location to use as the point-based representation of the Fixture.

Example

{
  "id": "11111111-1111-1111-1111-111111111111",
  "type": "Feature",
  "feature_type": "fixture",
  "geometry": {
    "type": "Polygon",
    "coordinates": [
      [
        [100.0, 0.0],
        [101.0, 0.0],
        [101.0, 1.0],
        [100.0, 1.0],
        [100.0, 0.0]
      ]
    ]
  },
  "properties": {
    "category": "desk",
    "name": null,
    "alt_name": null,
    "anchor_id": null,
    "display_point": {
      "type": "Point",
      "coordinates": [ 100.0, 1.0 ],
    },
    "level_id": "2222222-2222-2222-2222-222222222222"
  }
}

Property Capturing Rules

DISPLAY-POINT

  • SHOULD be present to explicitly indicate (and symbolize) the location of a point-based representation of a Fixture. (Illustration)
  • SHOULD be present to explicitly indicate (and symbolize) a collection of Fixtures that touch and possess the same category.
  • MUST be within the boundary of the Fixture.

Geometry Capturing Rules

  • The Venue Organization is responsible for establishing the scope and purpose of a Fixture. They are NOT defined by IMDF. When deciding the scope of the map data requirements, a Venue Organization SHOULD consider:
    • Venue Organizational (internal) needs.
    • General map purpose.
    • The use case model "driving" the map application.
    • The value that is derived through augmentation of the map with Fixtures.
    • Map data context, map scale and the relevance of a Fixture at each of the viewable map-scales.
    • The expected level of interaction between a pedestrian and the asset, and the degree to which the map application can enrich that "experience" through the presentation of these modeled assets.
    • Map aesthetic quality considerations.
  • Horizontal positional accuracy MUST be within tolerance.
  • Fixture features that touch SHOULD be merged when:
    • A comparison of the physical characteristics generates no distinct differences.
    • Modeling the assets separately offers no derivable benefit.
    • The map's aesthetic quality is enhanced by merging the features.

Category Specific Rules

"equipment"

"furniture"

  • Furniture MAY be modeled as a "furniture" Fixture. (Illustration)
  • Furniture MUST only be modeled if the presence of such items "...forms a clear expression of the theme(s)." and they are "...integral to the function of [the] map." Reference.

"obstruction"

  • An obstruction MAY be modeled as an "obstruction" Fixture.

"vegetation"

  • A vegetated area MAY be modeled as "vegetation". (Illustration)
  • The boundary SHOULD model a physical barrier whose contained area is not intended for pedestrian use.

"wall"

  • A wall that divides a pedestrian area MAY be modeled as a "wall". (Illustration)

"water"