cam_pos      = [-0.843676, 1.49729, -1.26777]';
cam_dir      = [-0.378722, 0.236701, 0.89473]';
cam_up       = [0.042824, 0.970189, -0.238537]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [1.22961, 0.069191, 0.502165]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;