cam_pos      = [-0.616586, 0.914186, -0.137893]';
cam_dir      = [0.603184, 0.0854236, -0.793015]';
cam_up       = [0.797335, -0.0388597, 0.602284]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.0274418, 1.32413, 0.121763]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;