glTF Working Group Meeting 2022-01-20

[robertlong]

OMI glTF Working Group Meeting 1/20/2022

This meeting will be on 1/20/2022 at 10:30 PM (UTC) / 2:30 PM (PST) in the OMI Discord within the #omi-weekly-meeting channel. During the meeting, we will be using the #omi-gltf-extensions channel to manage a speaker queue, post links, and for any sidebar discussions.

To be notified of this meeting and others, subscribe to the OMI Meetings and Events Calendar or add yourself to the @omi-gltf-subgroup role in the #roles channel of the OMI Discord.

Agenda

• OMI_audio_emitter
  • Add Contributors
  • Blender Addon Updates
• Collider extension
• Avatar Animation Retargeting

To propose another item for the agenda, comment below (preferably before the meeting).

[antpb]

Notes: mention of avatar humanoid style interop by Discord user tinyCornerstone. Mention of cataloging world by attributes like poly count, texture, filesize, bones, blend shapes, material count, rigging ( rigging is a hard problem )

[robertlong]

Spoke extracts some of this info on export for determining scene performance. You can relatively easily extract most of this info from the glTF file. Even in a glb where you can request just the JSON chunk of the file

[antpb]

Note on blender addon: Storing binary data from media (like audio/video) is difficult in Blender. May need to start smaller as a first pass. Mentioned in meeting agreement to move forward with glb only as the PR currently sits.

[antpb]

Notes Collider:
Mauve mentioned: define collision boxes and decide physics at a later time.
iFire mentioned: needing rigid, rigid dynamic, custom in the collider spec (may be blocked by deciding approach)
Mauve mentioned: static/dynamic or another that defines collision boxes
Robert mentioned: we should document physics engines and prior work. Document shapes and bodies(rigidbody, softbody, etc) would be good to document approaches: bullet, NVIDIA PhysX, rapier, godot custom physics

Can we get to stage 4 without object visibility? Robert said yes.
Lyuma: we need an option to disable shapes or colliders from being actual colliders. Avoid blocking all collisions.

Robert showed two physics engines, Rapier and Unity

Rapier defines a shape of a body using colliders, different shapes available. All gets bundled to collider description which holds the position information. Enables triggers. Finds intersections.

Mauve mentioned: should stay as close to popular engine terminology for searchability relative to different implementations of OMI. fire mentioned we should document those terms from each engine.

Lyuma mentioned: Do bodies require a collision shape to be a child?