Physical Dimensions service and 3D

[tomcrane]

Extend https://iiif.io/api/annex/services/#physical-dimensions and describe how it applies to Scene

Complexity cf 2D - the content resources (models) may have their own physical dimensions data as they are brought into the Scene

(This is not part of the Presentation API, it's an external service - at the moment, at least)

[tomcrane]

(very) unlike 2D, would we say that IIIF Scenes have a default phys dim of 1m per unit?

[tomcrane]

In the 99% case of a single model targeting the whole Scene, where that Scene has no phys dim service declared but the model being painted might have scale information, does the Scene inherit the scale of the model?

Or is that going to introduce unresolvable problems - if I later painted a second model in, what happens?

Maybe this is meaningless as a viewer that wanted to show a ruler for a single model Scene could just use the model's scale.

[tomcrane]

Consensus from DC meeting - a Scene does not have a default physical dimensions service of 1m-1 unit. But ability to assert a phys dim service is very important.

[azaroth42]

Eds to discuss and determine complexity -- is this a quick reference or are there issues to discuss