Panorama Stereographic projection "Little Planets" in gen!?


    Jun 12 2013 | 1:57 pm
    Hello
    Patching with Gen in this hi level is new to me, i need help.
    I like this:
    http://creativejs.com/2012/01/little-planet-street-view/
    There is a interactive online website you can check it self, its very funny but you
    need a browser with WebGL support -> Firefox.
    The basic is a 360° sphere panorama picture. ( http://de.wikipedia.org/wiki/Kugelpanorama )
    Can someone tell me how i can make this "Little Planets" in gen?
    Here is the GLSL shader code from the website(you can find this in the left top, press +):
    _________________________________________________________________________
    precision mediump float;
    uniform sampler2D texture;
    uniform float scale, aspect, time;
    uniform mat3 transform;
    varying vec2 v_texcoord;
    #define PI 3.141592653589793
    void main(){
    vec2 rads = vec2(PI * 2., PI);
    vec2 pnt = (v_texcoord - .5) * vec2(scale, scale * aspect);
    // Project to Sphere
    float x2y2 = pnt.x * pnt.x + pnt.y * pnt.y;
    vec3 sphere_pnt = vec3(2. * pnt, x2y2 - 1.) / (x2y2 + 1.);
    sphere_pnt *= transform;
    // Convert to Spherical Coordinates
    float r = length(sphere_pnt);
    float lon = atan(sphere_pnt.y, sphere_pnt.x);
    float lat = acos(sphere_pnt.z / r);
    gl_FragColor = texture2D(texture, vec2(lon, lat) / rads);
    }
    _________________________________________________________________________
    (Sorry if my english not good, i am better in german)
    Many thanks for the support and have a nice day
    Urs