I'm not sure if this is useful to anyone, but it turns out cubic panoramas are
very easy.  I just pointed a 90 degree perspective camera in all six
directions, and put the resulting hdr images on six faces of a cube.  The inset
in the example below is rendered with the cube edges on.  With a two-pass method
for radiosity (so all use the same cache data) the edges are completely
invisible.  Any discontinuities are only from the AA (or lack of), not from the
interface.  Aliasing is no problem as long as the original is nicely
anti-aliased and coarse enough.  Next step: OpenGL.

Note:  The edges show if interpolation is on, but this can be fixed by
increasing the camera angle to slightly larger than 90 degrees, only so there
is something to interpolate, rather than extrapolate.  Of course the faces must
be scaled accordingly, but that's just a little trig.

 - Ricky

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"triple_r" <nomail@nomail> wrote:
> I'm not sure if this is useful to anyone, but it turns out cubic panoramas are
> very easy.  I just pointed a 90 degree perspective camera in all six
> directions, and put the resulting hdr images on six faces of a cube.

If your only intention is to use the resulting shot in another POV scene, then
it's probably even better to use a spherical (lat/long) camera, so you just use
spherical projection when using the shot. No trouble with edges at all, no
problem with different shots using different radiosity data (because it's all
one single shot anyway), and virtually no problem with interpolation either.

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clipka wrote:
> If your only intention is to use the resulting shot in another POV scene,
> then it's probably even better to use a spherical (lat/long) camera, so
> you just use spherical projection when using the shot. No trouble with
> edges at all, no problem with different shots using different radiosity
> data (because it's all one single shot anyway), and virtually no problem
> with interpolation either.

But if the idea is using it in a panorama viewer, the "poles" of the sphere
usually look ugly.

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