8.6 Material reflectance schema

8.6.1 metadata

Metadata about the material.

Type: object
Required: Yes

8.6.1.1 name

The display name of the material, such as 'Red brick' or 'Dark asphalt'.

Type: string
Required: Yes

8.6.1.2 description

Short description of the material in 2 - 3 sentences.

Type: string
Required: Yes

8.6.1.3 uuid

Universally unique identifier for the material in 8-4-4-4-12 format, see en.wikipedia.org/wiki/Universally_unique_identifier. The uuid stays the same, even if version is updated.

Type: string
Pattern: \\b[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}\\b$
Required: Yes

8.6.1.4 materialVersion

The version number of the material, following semantic versioning (e.g., '1.0.0').

Type: string
Pattern: ^\\d+\\.\\d+\\.\\d+$
Required: Yes

8.6.1.5 openMaterialVersion

The version of the OpenMATERIAL 3D specification used, adhering to semantic versioning (e.g., '1.0.0').

Type: string
Pattern: ^\\d+\\.\\d+\\.\\d+$
Required: Yes

8.6.1.6 copyright

Type: string
Required: Yes

8.6.1.7 license

Describes the license for material distribution. Use an SPDX identifier for open-source licenses (e.g., 'MIT'), or provide a URL or filename for proprietary licenses.

Type: string
Required: Yes

8.6.1.8 author

Lists the author(s) of the material as a name, email, or company. Multiple authors should be comma-separated.

Type: string
Required: Yes

8.6.1.9 creationDate

The date and time of material creation, formatted as YYYYMMDDTHHMMSSZ according to ISO 8601 (e.g., '20240703T101728Z').

Type: string
Pattern: ^\\d{8}T\\d{6}Z$
Required: Yes

8.6.1.10 source

Source of the reflectance data. Was is measured, simulated, or taken from literature?

Type: string
Required: Yes

8.6.2 reflectance

Reflectance lookup table including relevant meta data.

Type: object
Required: Yes

8.6.2.1 wavelengths

List of all wavelengths in meters contained in the lookup table.

Type: array
Required: Yes

8.6.2.2 lookupTable

Array of reflectance values, with each item representing a different property. The array SHALL be sorted based on the columns starting with the first.

Type: array
Required: Yes

Columns of the table:

Column 1: Wavelength in meters.
Column 2: Incident elevation angle (= zenith angle) relative to the surface normal in rad.
Column 3: Exit elevation angle (= zenith angle) relative to the surface normal in rad.
Column 4: Exit azimuth angle in rad. For reflectance with incident and exit vectors on the same plane as the normal, exit azimuth angle is 0.
Column 5: Polarized plane angle in rad. This is the angle between the plane containing the incident, exit, and normal vector, and the plane of polarization.
Column 6: Amplitude within the linearly polarized plane. The amplitude is given as a relative value compared to an ideal reflector.
Column 7: Phase within the linearly polarized plane. If the phase is not taken into account, it is null.