Rendering a portion of an image to a quad

Is there an easy way to do this? I am working in ortho and would like to make an image the size of the whole screen while rendering only a portion of it onto a quad. The idea is that I would like to be able to move the quad around while keeping the image texture in place so that you see a different part of the image when you move the quad around (kind of like a flashlight effect, but rectangular). I think that I should approach it this way since I plan to have other elements in my scene.

When I try to do


I get null for both (no matter where I place these printlns in my code).

Well, fakeTex must be null then :wink: