Hi Marian,
I've not tried this, but:
On 14/04/12 17:47, Marian Weger wrote:
Is it somehow possible to get a 360 degree angle-of-view with the GEM camera inside a framebuffer?
Isn't there some easy way to do the same thing?
I don't think so.
You could use a vertex shader to implement your own projection algorithm[0] to reduce any strange effects from stitching together multiple perspective projections. Perhaps "angular fish eye"[1] for the "wide" direction only (modelling a cylinder instead of a sphere).
Almost surely[2] it will still be necessary to render a few wedges of the cylinder to get a full 360 without bad problems at the edge cut[3].
An example of a "bad problem" with full 360 wide angle camera: something directly opposite the direction of the center of the view gets drawn as a huge wide thing that crosses from near far left to near far right instead of two small things one that goes from near far left to the far left edge and the other that goes from near far right to the far right edge. Little ASCII diagram:
| <--------------------------------> | bad problem |--> <---| what it should really be
Claude
[0] http://www.google.co.uk/#q=vertex+shader+360+wide+angle+projection+-xbox [1] http://paulbourke.net/miscellaneous/domefisheye/fisheye/ [2] http://en.wikipedia.org/wiki/Almost_surely [3] http://en.wikipedia.org/wiki/Branch_point#Branch_cuts