diff --git a/libs/geom/include/psemek/geom/box.hpp b/libs/geom/include/psemek/geom/box.hpp
index 3e1c1512..d1f9858b 100644
--- a/libs/geom/include/psemek/geom/box.hpp
+++ b/libs/geom/include/psemek/geom/box.hpp
@@ -305,4 +305,22 @@ namespace psemek::geom
 		return b;
 	}
 
+	template <typename T, std::size_t N>
+	point<T, N> lerp(box<T, N> const & b, vector<T, N> const & v)
+	{
+		point<T, N> p;
+		for (std::size_t i = 0; i < N; ++i)
+			p[i] = lerp(b[i], v[i]);
+		return p;
+	}
+
+	template <typename T, std::size_t N>
+	vector<T, N> unlerp(box<T, N> const & b, point<T, N> const & p)
+	{
+		vector<T, N> v;
+		for (std::size_t i = 0; i < N; ++i)
+			v[i] = unlerp(b[i], p[i]);
+		return v;
+	}
+
 }