public void SetCamera(Matrix3D xfrm)
{
_xfrmInverse = xfrm;
_xfrm = _xfrmInverse.GetInverse();
_translation = _xfrmInverse.ExtractTranslation();
xfrm.ExtractBasis(
out _rightAxis, // x axis
out _upAxis, // y axis
out _forwardAxis // z axis
);
_rightAxis = -_rightAxis;
_bFrustumPlanesDirty = true;
}