cam_pos      = [0.669064, 1.62352, 0.304664]';
cam_dir      = [-0.713274, -0.500371, -0.490785]';
cam_up       = [-0.197877, 0.815513, -0.543859]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.894256, 0.386771, 0.905326]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;