Based on your followup post, I think you're confused. Binocular overlap doesn't magically give you double the perceived resolution. If it worked that way, everyone would have a way higher PPD, but it doesn't and they don't. For a naive calculation on resolution you should just use the per eye resolution.
As mentioned resolution on the centroid may be higher depending on the lens design, but there's so much dependent on the rendering pipeline and the optics that I don't think it's worth doing more than ballparking. If you're interested in HMD displays, Oliver Kreylos has posted a lot on resolution measurements over the past few years:
As mentioned resolution on the centroid may be higher depending on the lens design, but there's so much dependent on the rendering pipeline and the optics that I don't think it's worth doing more than ballparking. If you're interested in HMD displays, Oliver Kreylos has posted a lot on resolution measurements over the past few years:
* Optical Properties of Current VR HMDs http://doc-ok.org/?p=1414
* Measuring the Effective Resolution of Head-mounted Displays http://doc-ok.org/?p=1631
* The Display Resolution of Head-mounted Displays http://doc-ok.org/?p=1677
* The Display Resolution of Head-mounted Displays, Revisited http://doc-ok.org/?p=1694