FreeTrack Forum

Okey, I already mentioned this but let me post it as official request/suggestion

In short: when you move your head in pure X translation the camera is no longer looking straight at your head but at an angle. in FreeTrack this angle is interpreted as Yaw input, but in reality your head hasn't moved a single degree (cause you're just that pro). Using simple trigonometry this can be solved. Only one new input parameter is needed: the (centered) distance from R to the camera lens. Optionally a factor can be included allowing the user to define how much to compensate for parallax.


example calculation:

Input Data:
situation 1: head is looking straight foreward (and at the camera).
R is at (0,0,800)(mm) (X,Y,Z), meaning no translation has occured, and in side view the horizontal distance(Z) from R to the camera is 800mm

situation 2: head is looking straight foreward (not at the camera).
R is at (30,0,800)(mm), meaning 30mm X translation has occured

Calculation:
ParallaxYaw=ArcTan(X/Z)
ParallaxPitch=ArcTan(Y/Z)
TrueYaw=Yaw-(ParallaxYaw*ParallaxYawCompensationFactor)
TruePitch=Pitch-(ParallaxPitch*ParallaxPitchCompensationFactor)


As can be seen having a small translation, or a large distance from the camera are both effective ways to reduce the parallax problem. But for those of us who do not have the ability to move the camera farther away (including myself, as matter of fact I have my cam floating above my monitor looking at a mirror behind the monitor, just to get the few extra centimeters.. ) or that have a compulsive desire to translate several yards side to side, this option would be a great help

When you move around you turn a little to keep facing the monitor (camera) to avoid yaw rotation. This is how it should be, the monitor is the center of your vision and you always want to comfortably see it. Why would you want it any other way?

Take for example if you were to move to the extreme left and then try to yaw to the extreme left, this is difficult to do while still eyeballing the monitor but is made easier by the very thing you want to eliminate!

that's why I proposed a factor ;). Personally I don't know why anyone would want to disable 'relative translation', yet the option is given