Definition
Functional Requirements
Syntax
Semantics
Conformance Testing
Performance Assessment
1 Definition
Position and Orientation of an Object in a Virtual Environment, excluding velocity and acceleration, including Field of View.
2 Functional Requirements
- An Object may have one of the following attributes: Speech, Audio, Visual, 3D Model, Audio-Visual, Haptic, Smell, RADAR, LiDAR, Ultrasound.
- Accuracy is the estimated absolute difference between the measured spatial and angular values of each of CartPosition, SpherPosition, Orientation, and their true value.
- Field of View is expressed as Azimuth and Elevation.
3 Syntax
https://schemas.mpai.community/OSD/V1.5/data/PointOfView.json
4 Semantics
Table 1 provides the semantics of the components of Point of View. Note that:
- Each of Position and Orientation is provided either in Cartesian (X,Y,Z) or Spherical (r,φ,θ) Coordinates.
- Euler angles are indicated by (α,β,γ).
| Header | Point of View Header – Standard “OSD‑OPV‑Vx.y”. |
| MInstanceID | Identifier of the M-Instance (Virtual Space) where this Point of View is defined. |
| UEnvironmentID | Identifier of the U-Environment (Real Space) where this Point of View is defined. |
| PointOfViewID | Unique identifier of this Point of View instance. |
| PointOfViewTime | Time this Point of View was produced. |
| General | General classification data of the Object. |
| – CoordType | Coordinate type: one of Cartesian, Spherical, Geodesic, Toroidal. |
| – ObjectType | Type of the Object: one of Digital Human, Generic. |
| – MediaType | Media type: one of Speech, Audio, Visual, Audio-Visual, Haptic, Smell, RADAR, LiDAR, Ultrasound. |
| Position and Orientation | |
| – CartPosition (X,Y,Z) | Cartesian position (X, Y, Z) in metres. |
| – CartAccuracy (X,Y,Z) | Accuracy of each Cartesian position component (X, Y, Z) in metres. |
| – SpherPosition (r,φ,θ) | Spherical position (r, φ, θ) in metres and degrees. |
| – SpherAccuracy (r,φ,θ) | Accuracy of each spherical position component (r, φ, θ). |
| – Orientation (α,β,γ) | Euler angles (α, β, γ) representing the Object’s orientation in degrees. |
| – OrientAccuracy (α,β,γ) | Accuracy of each Euler angle (α, β, γ) in Orientation (degrees). |
| Aperture[] | Field of View expressed as Azimuth and Elevation. |
| – Azimuth | Azimuth angle (twice the half-angle, in degrees). |
| – Elevation | Elevation angle (twice the half-angle, in degrees). |
| FocalDistance | Focal distance of the Point of View (metres). |
| DataXMData | MPAI-PTF Data Exchange Metadata providing provenance, authorisation, legal, security, and confidence information associated with this Point of View in a trusted data exchange context. |
| DescrMetadata | Human-readable descriptive metadata of the Point of View (plain text, max 2048 characters). |
5 Conformance Testing
A Data instance conforms with Point of View (OSD‑OPV) if:
- The Data validates against the Point of View’s JSON Schema.
- All Data in the Point of View’s JSON Schema:
- Have the specified type.
- Validate against their JSON Schemas.
- Conform with their Data Qualifiers.
6 Performance Assessment
Not part of this specification.
