cam_pos      = [0.692672, 1.37522, -0.246427]';
cam_dir      = [-0.918982, -0.325042, -0.223205]';
cam_up       = [-0.285036, 0.938775, -0.193534]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.362353, 0.15193, 1.27064]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;