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MPEG_mesh_linking

Contributors

  • ISO/IEC SC29 WG3 (MPEG Systems) - Scene Description Breakout Group
  • Contacts

Status

Based on ISO/IEC FDIS 23090-14

Dependencies

Written against the glTF 2.0 spec.

Overview

MPEG_mesh_linking extension provides the possibility to link a mesh to another mesh in a glTF asset. The shadow mesh corresponds to regular mesh data as defined by glTF 2.0 without the MPEG_mesh_linking extension. The dependent mesh can be transformed/animated by relying on the shadow mesh. The MPEG_mesh_linking extension included into the dependent mesh links the dependent mesh and the shadow mesh and provides with the data and information which is used to achieve the ability to animate the dependent mesh. Hence, the shadow mesh is present in the glTF assets to assist in achieving the ability to apply transformation onto the dependent mesh.

MPEG_mesh_linking Properties

Type Description Required
correspondence integer Provides a reference to the accessor ✓ Yes
mesh integer Provides a reference to the shadow mesh ✓ Yes
pose integer Provides a reference to the accessor ✓ Yes
weights integer Provides a reference to the accessor No
extensions object JSON object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

MPEG_mesh_linking.correspondence

Provides a reference to the accessor, by specifying the accessor's index in accessors array, that describe the buffer where the correspondence values between the dependent mesh and its associated shadow mesh will be made available. The componentType of the referenced accessor shall be as indicated in ISO/IEC 23090-14:7.4 and the type shall be SCALAR.

  • Type: integer
  • Required: ✓ Yes
  • Minimum: >= 0

MPEG_mesh_linking.mesh

Provides a reference to the shadow mesh, by specifying the mesh index in meshes array, associated to the dependent mesh for which the correspondence values are established.

  • Type: integer
  • Required: ✓ Yes
  • Minimum: >= 0

MPEG_mesh_linking.pose

Provides a reference to the accessor, by specifying the accessor's index in accessors array, that describe the buffer where the transformation of the nodes associated to the dependent mesh will be made available. The componentType of the referenced accessor shall be FLOAT and the type shall be MAT4.

  • Type: integer
  • Required: ✓ Yes
  • Minimum: >= 0

MPEG_mesh_linking.weights

Provides a reference to the accessor, by specifying the accessor's index in accessors array, that describe the buffer where the “weights” to be applied to the morph targets of the shadow mesh associated to the dependent mesh will be made available. The componentType of the referenced accessor shall be FLOAT and the type shall be SCALAR.

  • Type: integer
  • Required: No
  • Minimum: >= 0

MPEG_mesh_linking.extensions

JSON object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: Extension

MPEG_mesh_linking.extras

Application-specific data.

  • Type: any
  • Required: No

Known Implementations

Resources

  • ISO/IEC FDIS 23090-14, Information technology — Coded representation of immersive media — Part 14: Scene Description
  • ISO/IEC WD 23090-24, Information technology — Coded representation of immersive media — Part 24: Conformance and Reference Software for Scene Description for MPEG Media

License

Copyright ISO/IEC 2022

The use of the "MPEG scene description extensions" is subject to the license as accessible here: https://standards.iso.org/ and is subject to the IPR policy as accessible here: https://www.iso.org/iso-standards-and-patents.html.