cam_pos      = [-0.136335, 1.56739, 0.737119]';
cam_dir      = [-0.948964, 0.0244269, -0.314439]';
cam_up       = [0.294217, 0.427675, -0.854711]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.151087, 1.20179, 0.549335]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;