cam_pos      = [-0.88181, 1.67208, -0.689458]';
cam_dir      = [-0.217315, 0.177756, 0.95978]';
cam_up       = [0.0140323, 0.983746, -0.179017]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [1.29808, 0.0338288, 0.287648]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;