Cube to fish-eye

kospanak

i want to write a program which can convert a cubemap to angular fish eye. i just don't know how to render the cubic sides on the sphere. could someone help me please?

P.S: i would be most delightful, if you could provide me with an algorithm or even a pseudo code.

Josh Code

: i want to write a program which can convert a cubemap to angular
: fish eye. i just don't know how to render the cubic sides on the
: sphere. could someone help me please?
:
: P.S: i would be most delightful, if you could provide me with an
: algorithm or even a pseudo code.
:

By "cube map", I assume you mean the texture is mapped assuming it is wrapped around a cube like cutting and folding a paper cube.

By "angular fish eye," I assume you mean something like a spherical map. Something like a flat map of an atlas where latitude and longitude are straight, orthogonal lines and at constant intervals of separation.

Maybe you could work out the math and make a program to convert the cube map to a flatmap that way. Visualize it like ray casting but make your ray directions correspond with the spherical coordinate system like latitude and longitude.

If you have some trouble, your first step could be making a fish eye using only one side of the cube. You could add more sides on from there.