Polarized 3D projector(x2)

Hello,
I hope this is the place to submit this question.
I made a small search and didn't find information on what I wanted to know, but I think it is quite possible that this kind of thing have been disscussed here already.

I am intersted in creating home made 3D streoscopic projector.
There was this article of how to do it with one projector by blocking one eye when a frame for the other eye is shown.
However, I want to do it like in the theaters.
That is, to have 2 projectors covered with some polarization material, and use polarized glasses.
This way you truly get two seperate images into each eye, simultaneously.
It shouldn't be to expensive?
Also, I would like to know if it is possible to do it with circular polarization instead of linear polariztion, and how it is actually done in the theaters?

Thank you.

You can get polarisation filters for camera lenses. Although I don't think that they have an orientation noted on them. If not, the places that supply schools with polarised panes of glass for experiments will be able to help (physics / chemistry equipment supply) but you'd have to jury rig some kind of holder one horizontal and one vertical. The optical properties of the glass might be a bit iffy though as its not designed for that.

I'm not sure how you get the projectors to show separate images though, as the normal stereo software shows different images on different frames, as opposed to two different images at the same time.

Hopefully I've helped with a part of the solution, just the difficult bits to come now...