From 6a9f7dd662afd5014c4b1bc0bed0339b56ff28d8 Mon Sep 17 00:00:00 2001
From: "Steven G. Johnson" <stevenj@alum.mit.edu>
Date: Tue, 20 Oct 2020 17:27:46 -0400
Subject: [PATCH] bugfix

---
 src/meepgeom.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/meepgeom.cpp b/src/meepgeom.cpp
index ae6217d14..99a82569d 100644
--- a/src/meepgeom.cpp
+++ b/src/meepgeom.cpp
@@ -1108,7 +1108,7 @@ void geom_epsilon::eff_chi1inv_matrix(meep::component c, symmetric_matrix *chi1i
 
   /* check for trivial case of only one object/material */
   if (material_type_equal(mat, mat_behind)) {
-    if (is_variable(mat)) eval_material_pt(mat, p_mat);
+    if (is_variable(mat)) eval_material_pt(mat, vec_to_vector3(v.center()));
     goto trivial;
   }