cam_pos      = [0.20714, 0.677036, -0.340804]';
cam_dir      = [0.878895, 0.261312, 0.399075]';
cam_up       = [-0.448149, 0.165709, 0.878467]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.217353, 1.26473, -0.349454]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;