cam_pos      = [0.189744, 1.6882, 0.839917]';
cam_dir      = [-0.935111, -0.273074, 0.225826]';
cam_up       = [-0.323733, 0.399196, -0.857811]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.191648, 1.16409, 0.614056]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;