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Figure 9: Reducing reconstruction
error with center reprojection.

render the scene from a camera A third issue is related to crop down to the new shared whatever is behind it, which made
with a standard frustum, and then reconstruction. If we look at Figure viewport area. all our effects look quite strange.
reproject twice to generate the 1 again, we can see that there are The final set of issues is due We tried writing depth with alpha,

left and right view from that. The regions in space that the left eye can to how we handle alpha-blended but that introduced a new set of
reprojection step does take twice see that the right one can’t, and vice objects. In the ALL 4 ONE engine, problems. In the end, the best way to
as long when we do that, but the versa. So we have no information on we have a separate pass for such handle both the alpha-blending and
results look significantly better, how to reconstruct that region from objects, sorted by depth, and we do the 3D stereo was to use reprojection

and it’s still faster than rendering the other view. One possibility is to not write out depth. This produces to render the opaque passes, and
the scene twice. Figure 9 shows place black bars to cover that area good results for transparency but then render the alpha passes using a
the result of this, with the left of the viewport, but that’s not very has the slight problem that we standard stereo projection.

side rendered with left-to-right appealing. Our final solution was to don’t have the depth information to In order to take that approach,
reprojection, and the right side expand the horizontal field of view so correctly reproject that object. The though, we have to do two things.

with a standard non-stereo view that region is outside of the desired end result is that alpha-blended First, we have to reproject depth
reprojected to both left and right. viewport, then after reprojection geometry looks like it’s painted onto values as well as color values, so
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