To get the 3D effect working you need to draw the scene from two different points - call them the eyes ;o)... Assuming the original camera position represents always the left eye, we need to claculate a new position for the right eyes, right ?
Due to the kind of matrix calculation and behavior of the view matrix and the mathematics all around there we need to move the camera first to the virtual world space origin, than rotate around the camera up vector using ROT_ANGLE as the value how many degrees the view need to be rotated. Afterwards we need to move the camera away from the worlds origin to get it placed at the right position... Did you get that ? It's even hard to explain in german, so may be much more harder to get my point due to my bad english...

At the end of the manipulation both cameras are placed at the same position but looking in different directions. This is not good in some times, as both cameras should look at the same point in front of it in the virtual space...To ensure this you need to define the distance of this point in front of the camera by setting ROT_POINT to any value different to 0.

Comparing the stuff with Ratchet and Clank:
If you keep the ROT_POINT a value of 7 to 9 than ratchet is almost the focus of the 3D view, which means the red and cyan part do mainly overlap at the same point...As more fare you look from ratchet as more is the distance between red and cyan bit....

If you would change the value being greater than 10 somewhot behind ratchet is being the focus...and if you leave it 0 than the actual player position (meaning the camera itself) is the focus....if you take your 3D glasses on with the different settings you may see that it's sometimes hard for your eyes if the distance wasn't set proper...

If the red/cyan parts are very far away from each other, start trying to set the rotation angle to a very low value first: like 0.3 ore something like that...

good luck