cam_pos      = [0.193647, 1.68934, 0.838975]';
cam_dir      = [-0.935111, -0.273074, 0.225826]';
cam_up       = [-0.322902, 0.394178, -0.860441]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.194111, 1.16711, 0.607512]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;