cam_pos      = [-0.0446123, 1.60217, 0.781222]';
cam_dir      = [-0.974863, -0.00805402, -0.222659]';
cam_up       = [0.195596, 0.447634, -0.872563]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.141908, 1.18926, 0.578293]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;