adding positionOffset in the schema of the anchor component

[ybinstock]

I added positionOffset in the schema of the anchor component to offset models that don't have a pivot point at the bottom.

For our organization, the models are being placed too far down and we thought others might have a similar problem or want to have access to the position from the XR anchor.

I introduced positionOffset into the schema and adding it to the positionVec3 for the setAttribute Position method.

[blairmacintyre]

can you submit this against the develop branch, please. We're doing dev there, and then shifting things to the master branch when we do an npm release.

[blairmacintyre]

And, have you tested this against the new version that supports vertical planes? I'm usually leery of pulling a position out of a composite matrix, then adding to it (order of operations, and all that) -- up till now, all the anchors have had y-up, so I'd like to make sure this works when the anchor is on the wall (and thus, y is in the X-Z plane)

[ybinstock]

Just changed to develop branch

And no I haven't tested the new version (didn't know there was one, very excited to test vertical planes!)

[blairmacintyre]

sorry, I never got around to doing this and forgot; this still good?

[blairmacintyre]

Just saw an update on this, which reminded me I never dealt with it (sorry). Can you summarize what's changed in the latest commit?