HMDQ tools for inspecting the VR headsets geometry - version 2.1.0 released

Just for anyone interested I have published hmdq-tools-2.1.0 (, which implement a new algorithm for FOV & HAM calculation. The new algo works correctly with headsets with total horizontal raw FOV bigger than 180 degrees. Currently there is only one - StarVR One :).

The data for the other headsets are not affected by the change.

I have also added StarVR One data to the hmdgdb (


Hmm… I suppose the compatibility mode (EDIT: …of the StarVR’s…) probably asks for perfectly symmetrical camera frusta, for uncompromisingly compatibility-seeking purposes, and just throws away the overlapping bits the device can presumably not show…(?)

…then again; In that case one might have expected the HAM to include those strips.

Good catch! :grinning:: Even though I am afraid that the perfectly symmetrical frusta are totally not needed (unless one is obsessed about the symmetry) as one can achieve even more perfect results by simply rendering what the headset actually can handle.

The dichotomy here is striking and it seems like each mode was defined by a different team (or maybe even a different company) :wink:. Raises the question about what one might actually see in the headset in the end. Unfortunately I no longer have the headset to run some visible FOV test app.

Oh! You had a StarVR in hand? That’s cool! How did you like it? :7

If nothing else; From what I hear, NVidia’s single-pass-stereo feature has a tendency to produce bad results with asymmetrical frusta, which is kind of unfortunate, since I believe every HMD since the Rift devkits have had them, and there are supposedly, contrary to what I have been believing, quite a few games out there that make use of it… :7

I had one :wink: in hand for a short try, but I could not really make much out of it for two reasons. First, my IPD is 72 mm, which is way out of the “optimal” position, second, I could not fit my glasses in because they were too wide. So in the end I just focused on more “scientific” activities.

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