cam_pos      = [0.514389, 1.54224, 0.244841]';
cam_dir      = [-0.911365, -0.374977, -0.169722]';
cam_up       = [-0.277167, 0.863945, -0.42045]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.404704, 0.447069, 1.18543]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;