cam_pos      = [0.261131, 1.06051, 0.405503]';
cam_dir      = [0.539017, 0.453851, -0.709563]';
cam_up       = [-0.579002, 0.81147, 0.0791964]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.813605, -0.489641, -0.931235]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;