Different projection matrix per viewpoint

[dcnieho]

And i have a related question. In an overlay, the sizes I should specify my objects in are in pixels, after setting the overlay to the correct resolution. I am having difficulty getting the size of the HMD's screen.

With the vive, I open a window with the default vizconnect setup for the Vive. I then try to get screen resolution:
print viz.MainWindow.getSize(mode=viz.WINDOW_PIXELS)
What is returned is [3840.0, 1080.0], which is the resolution of my desktop (two 1920x1080 screens, side by side) and not the Vive's resolution of 1080x1200 per eye. Similarly, the returned aspect ratio is 1.77777777778, which is the aspect ratio of one of my 1920x1080 screens.

Would you know how i can get the size of the Vive (or other HMD's) screen, instead of of those automatically opened desktop windows? And specifically, how to get the size of a single eye's screen, which is what I (think I) need?

Thanks!