cam_pos      = [-0.616586, 0.914186, -0.137893]';
cam_dir      = [-0.213128, 0.136735, -0.967409]';
cam_up       = [0.977021, 0.0325793, -0.210641]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.00361158, 1.3168, 0.186914]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;