Using on a 3D display

[moshevds]

I just watched the @standupmaths video, and tried this out on my "LG D2342P Cinema 3D" display. This is a normal desktop monitor with support for polarized 3D glasses.

The software mostly works fine: I needed to change js/vr/VREffect.js to always do renderStereo, and I also needed to change the horizontal field of view for both eyes. I did this by trial and error and values between 60 and 65 for rightDegrees and leftDegrees seemed to work well.

My question is:
How would I go ahead and calculate the correct field of view for my monitor, considering it is a 16:9 display?

If I would know how to calculate these, and support for this type of display is desired, I am willing to add some hotkey to switch to this mode. Unfortunately there is no way to automatically detect my setup, as I simply put on my polarized 3D glasses and enable side-by-side mode using the monitor's OSD menu.