[PD] texturing a circular image onto a hemisphere in GEM

[Alex]

Maybe a different subject will inspire some help?

basically, I have video that was shot on a mirrored spherical ball..
this gives a circular image inside a rectangular video, I've figured
out how to crop it so that I just get the square that surrounds the
circle, but I cannot figure out how to correctly map this texture onto
a sphere so that it is only on one hemisphere and so that the circle's
circumference is on a "great circle" of the sphere? [ie it the circle
is warped out so that it becomes a hemisphere].

I figure maybe I have to do some GEMgl stuff for this?

if anyone has done this, would you please share?

If not, any advice?

Thanks,
-Alex


On 10/10/07, Alex <x37v.alex at gmail.com> wrote:
> I have some panoramic video that I want to use to texture a hemisphere
> [or rather, the bottom half of a sphere].
>
> I cannot simply texture the sphere with the video because the warping
> is not correct.. it seems that I need some sort of non-rectangular
> warping of the image before I texture the object, or a non-rectangular
> mapping of the texture onto the sphere.
>
> Any ideas or advice?  Does anyone else have experience working with
> panoramic video in Gem?
>
> -Alex
>