cam_pos      = [-0.838938, 1.49781, -1.2659]';
cam_dir      = [-0.378722, 0.236701, 0.89473]';
cam_up       = [-0.000218659, 0.96672, -0.255838]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [1.23093, 0.129126, 0.486868]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;