Function lerp

lerp(a, b, t, dst?): Quat
Performs linear interpolation on two quaternions. Given quaternions a and b and interpolation coefficient t, returns a + t * (b - a).
Parameters
- a: Quat
  Operand quaternion.
- b: Quat
  Operand quaternion.
- t: number
  Interpolation coefficient.
- Optional dst: Quat
  quaternion to hold result. If not passed in a new one is created.
Returns Quat
The linear interpolated result.