diff -r f248e1434c3b -r df9628092285 src/cube.rs
--- a/src/cube.rs	Sat Oct 19 10:46:13 2024 -0500
+++ b/src/cube.rs	Mon Oct 21 08:44:23 2024 -0500
@@ -232,6 +232,10 @@
     fn dist_to(&self, other : &Self) -> f64 {
         self.log_dist(other).1
     }
+
+    fn tangent_origin(&self) -> Self::Tangent {
+        Loc([0.0, 0.0])
+    }
 }
 
 #[cfg(test)]