Aven in stereoscopic 3D

[Olly Betts]

On Tue, Feb 20, 2018 at 01:04:07AM +0000, Pedro Silva Pinto wrote:
> Your changes in the "stereo" branch work for me, except for the placement of
> the for loop, because that way both images render on my left eye, and the
> right eye is totally black. Remember that the change between left and right
> buffers occurs inside StartDrawing, so it needs to be inside the loop.

Oh yes, I had to move that for the colour filter stereo (where we want
both the images drawn in the same buffer) but forgot to undo that
change.

> As for the stereo effect: my visual assessment is that the code applies the
> same separation to all objects, regardless of their z-axis position. I even
> put a ruller against the screen to measure - it's the same separation
> always. I think that the subtle 3D effect you mentioned results only from
> the 3D objects being rendered in a different plane than the program window
> (or the screen frame, if using fullscreen). Then the brain takes over and
> completes the illusion.
> 
> I'll try different values for the constants involved in the math for
> glFrustum to see if I get measurable stereoscopic object separation. Will
> post my results.

Looking at the example I was working from again, I see I didn't
translate the gluLookAt() calls, which are the part that deals with
this.  I guess that is equivalent to glTranslate by half the eye
separation left/right depending on the eye, but I'd have to think
about it.

Cheers,
    Olly