function turn
observer.ts:329
A base orientation with a free-look offset turned onto it.
Both rotations are in the camera's own axes and in this order: yaw about the base camera's up, then pitch about the yawed camera's right. Reversed, pitching first tilts the axis the yaw then runs about, so a look that is up and to the left arrives rolled — the horizon goes off level for a gesture that never asked it to.
A centered offset returns the base quaternion itself rather than its product
with the identity. The product is exact for every field, but isCentered is
the claim the compositions rest on and stating it as a branch is what makes
it hold under a later change to multiply.
- baseQuat
- Undocumented
- lookLookOffset
- Undocumented
ReturnsQuat