cam_pos      = [-0.402122, 2.0221, -0.13873]';
cam_dir      = [0.685308, -0.218105, 0.694826]';
cam_up       = [-0.0153886, 0.949549, 0.31324]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.968361, 0.299726, -0.861011]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;