io_export_md3.py 文件源码

def Encode(self, normal):
        x = normal[0]
        y = normal[1]
        z = normal[2]
        # normalize
        l = math.sqrt((x*x) + (y*y) + (z*z))
        if l == 0:
            return 0
        x = x/l
        y = y/l
        z = z/l

        if (x == 0.0) & (y == 0.0) :
            if z > 0.0:
                return 0
            else:
                return (128 << 8)

        lng = math.acos(z) * 255 / (2 * math.pi)
        lat = math.atan2(y, x) * 255 / (2 * math.pi)
        retval = ((int(lat) & 0xFF) << 8) | (int(lng) & 0xFF)
        return retval