I believe, you are using a wrong approach for trying to produce stereoscopic or anaglyph images.

If i do understand it the right way, you you are trying to move an object infront of the camera and change the position in relation to the render camera.
But that is not, what the human left and right eyes will be seeing.

The left and right eye are away from each other a certain distance from each other. So the resulting angle and POV towards objects and the surrounding scenery are different from each other, not the position of an object infront of them.

Take a look at my blog-website and read and view a small basic tutorial i've wrote (besides a few other tutorials i've wrote on the same blog), to render images in Vue for anaglyph pictures creation:

http://arraxxon.blogspot.com/2009/08/basic-setup-to-render-left-and-right.html

Maybe this can be of help ...