OpenVR (aka SteamVR) provides the position of the vive controller. The question is where that point is exactly located on the controller itself?
To be more specific, where (on the hardware) the following method call (from OpenVR) refers to?
virtual void GetDeviceToAbsoluteTrackingPose( ETrackingUniverseOrigin eOrigin, float fPredictedSecondsToPhotonsFromNow, VR_ARRAY_COUNT(unTrackedDevicePoseArrayCount) TrackedDevicePose_t *pTrackedDevicePoseArray, uint32_t unTrackedDevicePoseArrayCount ) = 0;