Add quack and duck to bitecs

[stalgiag]

This migrates duck and quack to bitecs and recreates what I believe was the original intended behavior:

• Duck can be generated with '/duck'
• Duck is networked, grabbable, and responds to physics
• Duck play quack sound effect locally on grab, occasionally the quack is "special"

I tried to keep everything as near to the original as possible since this is an early change for me. I added comments to the diffs for situations where this was awkward.

part of #5899

[keianhzo]

LGTM, I just left a few of comments. Feel free to merge or address the feedback.

[stalgiag]

These three lines and the avatarPov line are repeated twice now. Feels like they should be a component down the line ("spawn-at-view").

[keianhzo]

Yeah, in most cases we use this for spawning media in front of the user:
https://github.com/mozilla/hubs/blob/a0e5eee06395c5cfeb604e03dab03e9a33077620/src/scene-entry-manager.js#L244
If we add a component for this we can also refactor those methods.

[Exairnous]

Does this preserve the reverse physics (floating) when the duck is scaled?

[stalgiag]

Does this preserve the reverse physics (floating) when the duck is scaled?

Good catch! I wasn't aware of this easter egg feature and thought the physics were similar to the default floatyObject. It looks like this behavior is a unique case exclusively for ducks. We don't currently have a duck system and one shouldn't be made for modifying physics.

I can add a flag on floatyObject which would allow for reuse.

[stalgiag]

I modified the FloatyObject component to handle Duck-specific physics. I made a new flag within FloatyObject in case we want to reuse this behavior elsewhere. The FloatyObject component could quickly become unwieldy if there are many different unique physics cases like this one. If this is the situation then I can decouple from floatyObject and make a new new helium component & system.

[Exairnous]

Thanks! Yeah, it's a bit hidden, but really fun and useful. There is a way with the old loader to have arbitrary GLBs behave as ducks, so we've been able to hack in flying/floating objects that way, e.g. Floating_Lantern.zip.

So hopefully either that'll still work, or your suggestion of a helium component sounds good :)

[keianhzo]

I had no idea about this behavior 😅 LGTM!