cam_pos      = [-0.355515, 0.942387, 0.664338]';
cam_dir      = [-0.582511, 0.447224, -0.678728]';
cam_up       = [0.812797, 0.313768, -0.490827]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.00870754, 1.11398, 0.726546]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;