diff --git a/libs/geom/include/psemek/geom/matrix.hpp b/libs/geom/include/psemek/geom/matrix.hpp
index 03dc9ed3..a79ac90d 100644
--- a/libs/geom/include/psemek/geom/matrix.hpp
+++ b/libs/geom/include/psemek/geom/matrix.hpp
@@ -377,6 +377,16 @@ namespace psemek::geom
 		return r;
 	}
 
+	template <typename T, std::size_t N>
+	matrix<T, N, N> outer_product(vector<T, N> const & v1, vector<T, N> const & v2)
+	{
+		matrix<T, N, N> r;
+		for (std::size_t i = 0; i < N; ++i)
+			for (std::size_t j = 0; j < N; ++j)
+				r[i][j] = v1[i] * v2[j];
+		return r;
+	}
+
 	template <typename T, std::size_t R, std::size_t C>
 	std::ostream & operator << (std::ostream & os, matrix<T, R, C> const & m)
 	{