def arcball_map_to_sphere ( point , center , radius ) : v0 = ( point [ 0 ] - center [ 0 ] ) / radius v1 = ( center [ 1 ] - point [ 1 ] ) / radius n = v0 * v0 + v1 * v1 if n > 1.0 : # position outside of sphere n = math . sqrt ( n ) return numpy . array ( [ v0 / n , v1 / n , 0.0 ] ) else : return numpy . array ( [ v0 , v1 , math . sqrt ( 1.0 - n ) ] )
create sphere through data points in python
Return unit sphere coordinates from window coordinates .
def arcball_map_to_sphere(point, center, radius):
    """Return unit sphere coordinates from window coordinates."""
    v0 = (point[0] - center[0]) / radius
    v1 = (center[1] - point[1]) / radius
    n = v0*v0 + v1*v1
    if n > 1.0:
        # position outside of sphere
        n = math.sqrt(n)
        return numpy.array([v0/n, v1/n, 0.0])
    else:
        return numpy.array([v0, v1, math.sqrt(1.0 - n)])