cam_pos      = [-0.824496, 1.27863, -0.368526]';
cam_dir      = [-0.124238, 0.145597, 0.981512]';
cam_up       = [0.424277, 0.901983, -0.0800956]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [1.19297, -0.540621, 0.231199]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;