diff --git a/src/basics.cc b/src/basics.cc
index e35a48f..63ffd5c 100644
--- a/src/basics.cc
+++ b/src/basics.cc
@@ -15,6 +15,9 @@
 #pragma mark - Vectors
 
 const Vector3 Vector3::Zero = Vector3();
+const Vector3 Vector3::X = Vector3(1, 0, 0);
+const Vector3 Vector3::Y = Vector3(0, 1, 0);
+const Vector3 Vector3::Z = Vector3(0, 0, 1);
 
 
 /*
diff --git a/src/basics.h b/src/basics.h
index b323f6c..2ec9a27 100644
--- a/src/basics.h
+++ b/src/basics.h
@@ -38,6 +38,9 @@ struct Vector3
     Vector3 &normalize();
 
     static const Vector3 Zero;
+    // Unit vectors in each of the three cartesian directions.
+    static const Vector3 X, Y, Z;
+
     float x, y, z;
 };