cam_pos      = [-0.488703, 1.00932, 1.68889]';
cam_dir      = [0.944457, 0.311679, -0.104201]';
cam_up       = [-0.282678, 0.932179, 0.22613]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.222927, 0.244873, -1.28812]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;