Reference glTF 2.0 spec about 3d-tiles

[pjcozzi]

CC CesiumGS/3d-tiles-samples#15

[nitrologic]

What is the status of b3dm? If there is no immediate plan to adopt GLTF 2.0 then perhaps this spec should be considered abandonware and a deprecation notice added.

[pjcozzi]

@nitrologic Cesium's 3D Tiles renderer implementation supports glTF 2.0 - and converts glTF 1.0 to 2.0 on-the-fly for backwards compatibility - this issue is a reminder to update the b3dm/i3dm spec before we put the finishing touches on it for a final 1.0.

[nitrologic]

Thanks for the prompt reply Patrick. I have yet to see a 2.0 based b3dm in the wild so was concerned my failure to create a conforming asset was due to not reading the fine print which currently states "Batched 3D Model uses glTF 1.0 with the KHR_binary_glTF extension."

[pjcozzi]

I believe the same tilesets in the Cesium repo are glTF 2.0.

[nitrologic]

Exactly which tilesets in what repo?

[lilleyse]

I actually don't think they have been updated yet. I have a branch in 3d-tiles-tools but haven't had a chance to finish it up yet: https://github.com/AnalyticalGraphicsInc/3d-tiles-tools/tree/2.0-samples-generator

[ggetz]

Resolved in #301