scene 10 {                      /* initial scene, big sphere with ray */
    campos < 0, 1-1*t, -1 >
    lookat < 0, 1-1*t,  0 >
    up     < 0, 1, 0 >
    sphere {
        < 0, 0, 0>, 0.5
        rays 1
        direction < 0, 0, -1 >
        color     < 0, 1, 0 >
    }
}

////////////////////////////////////////////////////////////////////////////////

scene 3 {                      /* flight along a ray */
    campos < -0.5+0.2*t, 0.2, -0.5 >
    lookat < -0.0+0.7*t, 0,      0 >
    up     < 0, 1, 0 >
    sphere {
        < 0, 0, 0>, 0.1
        rays 1
        direction < 1, 0, 0 >
        color     < 0, 1, 0 >
    }
}

////////////////////////////////////////////////////////////////////////////////

scene 3 {                       /* two interconnected spheres */
    campos < 0, 0, -2.0+1.0*t >
    lookat < 0, 0,  0 >
    up     < 0, 1, 0 >
    sphere {
        < -0.5, 0, 0>, 0.1
        rays 1
        direction < 1, 0, 0 >
        color     < 0, 1, 0 >
    }
    sphere {
        <  0.5, 0, 0>, 0.1
    }
}

////////////////////////////////////////////////////////////////////////////////

scene 8 {                      /* first slight reflection */
    campos < 0, 0.7, -1 >
    lookat < -0.3+0.6*t, 0,  0.5 >
    up     < 0, 1, 0 >
    sphere {
        < 0, 0, 1.1 >, 0.1
    }
    sphere {
        < -0.3, 0, 0>, 0.1
        rays 1
        direction < 0.3, 0, 1 >
        color     < 0, 1, 0>
    }
}

////////////////////////////////////////////////////////////////////////////////

scene 8 {                      /* multiple reflection */
    campos < -1.5+1*t, 0.7, 0.6 >
    lookat < 1, -0.5,  0.5 >
    up     < 0, 1, 0 >
    sphere {
        < 0, 0, 1.1 >, 0.1
    }
    sphere {
        < -0.3, 0, 0>, 0.1
        rays 1
        direction < 0.3, 0, 1 >
        color     < 0, 1, 0>
    }
    sphere {
        < 0.29, 0, 0>, 0.1
    }
    sphere {
        < 0.6, 0, 1>, 0.1
    }
}

////////////////////////////////////////////////////////////////////////////////

scene 10 {                       /* first spread */
    campos < 0, 0.5, -1+0.5*t >
    lookat < 0, 0-0.5*t, 1 >
    up     < 0, 1, 0 >
    sphere {
        < 0, 0, 0>, 0.1
        rays 6
        direction < 0.5-1*t, 0, 3 >
        color     < 0, 1, 0+0.5*t >
    }
    sphere {
        <  0, 0, 1 >, 0.2
    }
}

////////////////////////////////////////////////////////////////////////////////

scene 10 {                       /* first animation */
    campos < -0.23, 0.2, -0.4 >
    lookat < 0, 0, 1 >
    up     < 0, 1, 0 >
    sphere {
        < 0, 0, 0>, 0.1
        rays 1
        direction < 0, 0, 1 >
        color     < 0, 1, 0+0.5*t >
    }
    sphere {
        <  0.2-0.4*t, 0, 1 >, 0.1
    }
}

////////////////////////////////////////////////////////////////////////////////

scene 10 {                       /* collision */
    campos < -1-3.9*sin(0.45*t+0), 0, 0-3.9*cos(0.45*t+0) >
    lookat < -1, 0, 0 >
    up     < 0, 1, 0 >
    sphere {
        < -2, 0, 0 >, 0.2
        rays 23
        direction < 2, 0+0.15*sin(2*t+0), 0+0.15*cos(2*t+0) >
        color < 0, 0.75+0.25*sin(2*t+0), 0.25+0.25*cos(2*t+0) >
    }
    sphere {
        < 1-2*t, 0, 0 >, 0.2
    }
}

////////////////////////////////////////////////////////////////////////////////

scene 10 {                          /* "planets" */
    campos < 0+1*sin(1*t+0), 0, 0+1*cos(1*t+0) >
    lookat < 0, 0, 0 >
    up     < 0, 1, 0 >
    sphere {
        < 0, 0.4, 0 >, 0.4
        rays 11
        direction < 0+0.05*sin(2*t+0), -2.3, 0+0.05*cos(2*t+0) >
        color < 0, 0.75+0.25*sin(2*t+0), 0.25+0.25*cos(2*t+0) >
    }
    sphere {
        < 0, -2.2, 0 >, 2.0
    }
}

////////////////////////////////////////////////////////////////////////////////

scene 15 {                          /* huge spheres */
    campos < 0+1.5*sin(0.47*t+1.23),
        1.8, 0+1.5*cos(0.47*t+1.23) >
    lookat < 0, 0.5, 0 >
    up     < 0, 1, 0 >
    sphere {
        < 0, -3, 0 >, 0.1
        rays 6
        direction < 0+0.02*sin(2*t+0), 3.9, 0+0.02*cos(2*t+0) >
        color < 0, 0.75+0.25*sin(2*t+0), 0.25+0.25*cos(2*t+0) >
    }
    sphere {  // "tingling" sphere
        < 0+0.02*sin(3.9*t+0), 1.3, 0+0.02*cos(3.9*t+0) >, 0.2
    }
    // large spheres
    sphere <-0.5,0,-0.5>,0.65
    sphere <+0.5,0,-0.5>,0.65
    sphere <-0.5,0,+0.5>,0.65
    sphere <+0.5,0,+0.5>,0.65
}

////////////////////////////////////////////////////////////////////////////////