cam_pos      = [-0.582586, 1.15128, 0.774321]';
cam_dir      = [-0.367562, 0.325136, -0.871312]';
cam_up       = [0.917097, 0.282239, -0.281557]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.205317, 1.20041, 0.534555]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;