Investigate using FamilyInstance.Symbol for improved instancing

[corybarr]

(This is arguably not necessary for GTM.)

It might be possible to enhance instancing by using the FamilySymbol member of an element's FamilyInstance object. For example, when instancing via hashing geometry objects, only two of these 5 benches instance. However, they all share the same Symbol reference:

A point of confusion is that these benches export with differing numbers of verts and faces, which is why they fail the hash test for instancing. However, they look like genuine instances in other ways.

It might be possible to do away with hashing geometry data completely. The addin spends ~50% of its time serializing the data to hash.

[r-veenstra]

@corybarr is this still relevant for GTM?

[corybarr]

I think it's more of a need before open sourcing. If we plan to open-source at GTM, then I say yes.