diff --git a/tests/regression_tests/filter_mesh/inputs_true.dat b/tests/regression_tests/filter_mesh/inputs_true.dat
index 6755a64c8..919347d69 100644
--- a/tests/regression_tests/filter_mesh/inputs_true.dat
+++ b/tests/regression_tests/filter_mesh/inputs_true.dat
@@ -1,332 +1,56 @@
 <?xml version='1.0' encoding='utf-8'?>
 <geometry>
-  <cell fill="200" id="1" region="-6 34 -35" universe="0" />
-  <cell fill="201" id="2" region="-6 35 -36" universe="0" />
-  <cell id="3" material="8" region="-7 31 -32" universe="0" />
-  <cell id="4" material="9" region="-5 32 -33" universe="0" />
-  <cell id="5" material="12" region="-5 33 -34" universe="0" />
-  <cell id="6" material="11" region="-5 36 -37" universe="0" />
-  <cell id="7" material="10" region="-5 37 -38" universe="0" />
-  <cell id="8" material="7" region="-7 38 -39" universe="0" />
-  <cell id="9" material="9" region="6 -7 32 -38" universe="0" />
-  <cell id="10" material="5" region="7 -8 31 -39" universe="0" />
-  <cell id="11" material="6" region="5 -6 32 -34" universe="0" />
-  <cell id="12" material="7" region="5 -6 36 -38" universe="0" />
-  <cell id="21" material="1" region="-1" universe="1" />
-  <cell id="22" material="2" region="1 -2" universe="1" />
-  <cell id="23" material="3" region="2" universe="1" />
-  <cell id="24" material="3" region="-3" universe="2" />
-  <cell id="25" material="2" region="3 -4" universe="2" />
-  <cell id="26" material="3" region="4" universe="2" />
-  <cell id="27" material="1" region="-1" universe="3" />
-  <cell id="28" material="2" region="1 -2" universe="3" />
-  <cell id="29" material="4" region="2" universe="3" />
-  <cell id="30" material="4" region="-3" universe="4" />
-  <cell id="31" material="2" region="3 -4" universe="4" />
-  <cell id="32" material="4" region="4" universe="4" />
-  <cell id="50" material="3" region="34 -35" universe="5" />
-  <cell fill="100" id="60" region="34 -35" universe="6" />
-  <cell id="70" material="4" region="35 -36" universe="7" />
-  <cell fill="101" id="80" region="35 -36" universe="8" />
-  <lattice id="100" name="Fuel assembly (lower half)">
-    <pitch>1.26 1.26</pitch>
-    <dimension>17 17</dimension>
-    <lower_left>-10.71 -10.71</lower_left>
-    <universes>
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
-1 1 1 1 1 2 1 1 2 1 1 2 1 1 1 1 1 
-1 1 1 2 1 1 1 1 1 1 1 1 1 2 1 1 1 
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
-1 1 2 1 1 2 1 1 2 1 1 2 1 1 2 1 1 
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
-1 1 2 1 1 2 1 1 2 1 1 2 1 1 2 1 1 
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
-1 1 2 1 1 2 1 1 2 1 1 2 1 1 2 1 1 
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
-1 1 1 2 1 1 1 1 1 1 1 1 1 2 1 1 1 
-1 1 1 1 1 2 1 1 2 1 1 2 1 1 1 1 1 
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 </universes>
-  </lattice>
-  <lattice id="101" name="Fuel assembly (upper half)">
-    <pitch>1.26 1.26</pitch>
-    <dimension>17 17</dimension>
-    <lower_left>-10.71 -10.71</lower_left>
-    <universes>
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
-3 3 3 3 3 4 3 3 4 3 3 4 3 3 3 3 3 
-3 3 3 4 3 3 3 3 3 3 3 3 3 4 3 3 3 
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
-3 3 4 3 3 4 3 3 4 3 3 4 3 3 4 3 3 
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
-3 3 4 3 3 4 3 3 4 3 3 4 3 3 4 3 3 
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
-3 3 4 3 3 4 3 3 4 3 3 4 3 3 4 3 3 
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
-3 3 3 4 3 3 3 3 3 3 3 3 3 4 3 3 3 
-3 3 3 3 3 4 3 3 4 3 3 4 3 3 3 3 3 
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
-3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 </universes>
-  </lattice>
-  <lattice id="200" name="Core lattice (lower half)">
-    <pitch>21.42 21.42</pitch>
-    <dimension>21 21</dimension>
-    <lower_left>-224.91 -224.91</lower_left>
-    <universes>
-5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 
-5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 
-5 5 5 5 5 5 5 6 6 6 6 6 6 6 5 5 5 5 5 5 5 
-5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 5 5 5 5 5 
-5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 5 5 
-5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 5 
-5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 5 
-5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 
-5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 
-5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 
-5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 
-5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 
-5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 
-5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 
-5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 5 
-5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 5 
-5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 5 5 5 5 
-5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 5 5 5 5 5 
-5 5 5 5 5 5 5 6 6 6 6 6 6 6 5 5 5 5 5 5 5 
-5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 
-5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 </universes>
-  </lattice>
-  <lattice id="201" name="Core lattice (lower half)">
-    <pitch>21.42 21.42</pitch>
-    <dimension>21 21</dimension>
-    <lower_left>-224.91 -224.91</lower_left>
-    <universes>
-7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 
-7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 
-7 7 7 7 7 7 7 8 8 8 8 8 8 8 7 7 7 7 7 7 7 
-7 7 7 7 7 8 8 8 8 8 8 8 8 8 8 8 7 7 7 7 7 
-7 7 7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 7 7 
-7 7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 7 
-7 7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 7 
-7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 
-7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 
-7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 
-7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 
-7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 
-7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 
-7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 
-7 7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 7 
-7 7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 7 
-7 7 7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 7 7 
-7 7 7 7 7 8 8 8 8 8 8 8 8 8 8 8 7 7 7 7 7 
-7 7 7 7 7 7 7 8 8 8 8 8 8 8 7 7 7 7 7 7 7 
-7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 
-7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 </universes>
-  </lattice>
-  <surface coeffs="0.0 0.0 0.41" id="1" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 0.475" id="2" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 0.56" id="3" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 0.62" id="4" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 187.6" id="5" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 209.0" id="6" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 229.0" id="7" type="z-cylinder" />
-  <surface boundary="vacuum" coeffs="0.0 0.0 249.0" id="8" type="z-cylinder" />
-  <surface boundary="vacuum" coeffs="-229.0" id="31" type="z-plane" />
-  <surface coeffs="-199.0" id="32" type="z-plane" />
-  <surface coeffs="-193.0" id="33" type="z-plane" />
-  <surface coeffs="-183.0" id="34" type="z-plane" />
-  <surface coeffs="0.0" id="35" type="z-plane" />
-  <surface coeffs="183.0" id="36" type="z-plane" />
-  <surface coeffs="203.0" id="37" type="z-plane" />
-  <surface coeffs="215.0" id="38" type="z-plane" />
-  <surface boundary="vacuum" coeffs="223.0" id="39" type="z-plane" />
+  <cell id="1" material="1" region="1 -2 3 -4 10 -9" universe="1" />
+  <cell id="2" material="2" region="~(1 -2 3 -4) (5 -6 7 -8) 10 -9" universe="1" />
+  <surface coeffs="-5.0" id="1" name="minimum x" type="x-plane" />
+  <surface coeffs="5.0" id="2" name="maximum x" type="x-plane" />
+  <surface coeffs="-5.0" id="3" name="minimum y" type="y-plane" />
+  <surface coeffs="5.0" id="4" name="maximum y" type="y-plane" />
+  <surface boundary="reflective" coeffs="-10.0" id="5" name="minimum x" type="x-plane" />
+  <surface boundary="reflective" coeffs="10.0" id="6" name="maximum x" type="x-plane" />
+  <surface boundary="reflective" coeffs="-10.0" id="7" name="minimum y" type="y-plane" />
+  <surface boundary="reflective" coeffs="10.0" id="8" name="maximum y" type="y-plane" />
+  <surface boundary="vacuum" coeffs="10.0" id="9" type="z-plane" />
+  <surface boundary="vacuum" coeffs="-10.0" id="10" type="z-plane" />
 </geometry>
 <?xml version='1.0' encoding='utf-8'?>
 <materials>
-  <material depletable="true" id="1" name="UOX fuel">
-    <density units="g/cm3" value="10.062" />
-    <nuclide ao="4.9476e-06" name="U234" />
-    <nuclide ao="0.00048218" name="U235" />
-    <nuclide ao="0.021504" name="U238" />
-    <nuclide ao="1.0801e-08" name="Xe135" />
-    <nuclide ao="0.045737" name="O16" />
+  <material depletable="true" id="1">
+    <density units="g/cm3" value="10.0" />
+    <nuclide ao="1.0" name="U235" />
   </material>
-  <material id="2" name="Zircaloy">
-    <density units="g/cm3" value="5.77" />
-    <nuclide ao="0.5145" name="Zr90" />
-    <nuclide ao="0.1122" name="Zr91" />
-    <nuclide ao="0.1715" name="Zr92" />
-    <nuclide ao="0.1738" name="Zr94" />
-    <nuclide ao="0.028" name="Zr96" />
-  </material>
-  <material id="3" name="Cold borated water">
-    <density units="atom/b-cm" value="0.07416" />
-    <nuclide ao="2.0" name="H1" />
-    <nuclide ao="1.0" name="O16" />
-    <nuclide ao="0.000649" name="B10" />
-    <nuclide ao="0.002689" name="B11" />
-    <sab name="c_H_in_H2O" />
-  </material>
-  <material id="4" name="Hot borated water">
-    <density units="atom/b-cm" value="0.06614" />
-    <nuclide ao="2.0" name="H1" />
-    <nuclide ao="1.0" name="O16" />
-    <nuclide ao="0.000649" name="B10" />
-    <nuclide ao="0.002689" name="B11" />
-    <sab name="c_H_in_H2O" />
-  </material>
-  <material id="5" name="Reactor pressure vessel steel">
-    <density units="g/cm3" value="7.9" />
-    <nuclide name="Fe54" wo="0.05437098" />
-    <nuclide name="Fe56" wo="0.88500663" />
-    <nuclide name="Fe57" wo="0.0208008" />
-    <nuclide name="Fe58" wo="0.00282159" />
-    <nuclide name="Ni58" wo="0.0067198" />
-    <nuclide name="Ni60" wo="0.0026776" />
-    <nuclide name="Mn55" wo="0.01" />
-    <nuclide name="Cr52" wo="0.002092475" />
-    <nuclide name="C0" wo="0.0025" />
-    <nuclide name="Cu63" wo="0.0013696" />
-  </material>
-  <material id="6" name="Lower radial reflector">
-    <density units="g/cm3" value="4.32" />
-    <nuclide name="H1" wo="0.0095661" />
-    <nuclide name="O16" wo="0.0759107" />
-    <nuclide name="B10" wo="3.08409e-05" />
-    <nuclide name="B11" wo="0.000140499" />
-    <nuclide name="Fe54" wo="0.035620772088" />
-    <nuclide name="Fe56" wo="0.579805982228" />
-    <nuclide name="Fe57" wo="0.01362750048" />
-    <nuclide name="Fe58" wo="0.001848545204" />
-    <nuclide name="Ni58" wo="0.055298376566" />
-    <nuclide name="Mn55" wo="0.018287" />
-    <nuclide name="Cr52" wo="0.145407678031" />
-    <sab name="c_H_in_H2O" />
-  </material>
-  <material id="7" name="Upper radial reflector / Top plate region">
-    <density units="g/cm3" value="4.28" />
-    <nuclide name="H1" wo="0.0086117" />
-    <nuclide name="O16" wo="0.0683369" />
-    <nuclide name="B10" wo="2.77638e-05" />
-    <nuclide name="B11" wo="0.000126481" />
-    <nuclide name="Fe54" wo="0.035953677186" />
-    <nuclide name="Fe56" wo="0.585224740891" />
-    <nuclide name="Fe57" wo="0.01375486056" />
-    <nuclide name="Fe58" wo="0.001865821363" />
-    <nuclide name="Ni58" wo="0.055815129186" />
-    <nuclide name="Mn55" wo="0.0184579" />
-    <nuclide name="Cr52" wo="0.146766614995" />
-    <sab name="c_H_in_H2O" />
-  </material>
-  <material id="8" name="Bottom plate region">
-    <density units="g/cm3" value="7.184" />
-    <nuclide name="H1" wo="0.0011505" />
-    <nuclide name="O16" wo="0.0091296" />
-    <nuclide name="B10" wo="3.70915e-06" />
-    <nuclide name="B11" wo="1.68974e-05" />
-    <nuclide name="Fe54" wo="0.03855611055" />
-    <nuclide name="Fe56" wo="0.627585036425" />
-    <nuclide name="Fe57" wo="0.014750478" />
-    <nuclide name="Fe58" wo="0.002000875025" />
-    <nuclide name="Ni58" wo="0.059855207342" />
-    <nuclide name="Mn55" wo="0.019794" />
-    <nuclide name="Cr52" wo="0.157390026871" />
-    <sab name="c_H_in_H2O" />
-  </material>
-  <material id="9" name="Bottom nozzle region">
-    <density units="g/cm3" value="2.53" />
-    <nuclide name="H1" wo="0.0245014" />
-    <nuclide name="O16" wo="0.1944274" />
-    <nuclide name="B10" wo="7.89917e-05" />
-    <nuclide name="B11" wo="0.000359854" />
-    <nuclide name="Fe54" wo="0.030411411144" />
-    <nuclide name="Fe56" wo="0.495012237964" />
-    <nuclide name="Fe57" wo="0.01163454624" />
-    <nuclide name="Fe58" wo="0.001578204652" />
-    <nuclide name="Ni58" wo="0.047211231662" />
-    <nuclide name="Mn55" wo="0.0156126" />
-    <nuclide name="Cr52" wo="0.124142524198" />
-    <sab name="c_H_in_H2O" />
-  </material>
-  <material id="10" name="Top nozzle region">
-    <density units="g/cm3" value="1.746" />
-    <nuclide name="H1" wo="0.035887" />
-    <nuclide name="O16" wo="0.2847761" />
-    <nuclide name="B10" wo="0.000115699" />
-    <nuclide name="B11" wo="0.000527075" />
-    <nuclide name="Fe54" wo="0.02644016154" />
-    <nuclide name="Fe56" wo="0.43037146399" />
-    <nuclide name="Fe57" wo="0.0101152584" />
-    <nuclide name="Fe58" wo="0.00137211607" />
-    <nuclide name="Ni58" wo="0.04104621835" />
-    <nuclide name="Mn55" wo="0.0135739" />
-    <nuclide name="Cr52" wo="0.107931450781" />
-    <sab name="c_H_in_H2O" />
-  </material>
-  <material id="11" name="Top of fuel assemblies">
-    <density units="g/cm3" value="3.044" />
-    <nuclide name="H1" wo="0.0162913" />
-    <nuclide name="O16" wo="0.1292776" />
-    <nuclide name="B10" wo="5.25228e-05" />
-    <nuclide name="B11" wo="0.000239272" />
-    <nuclide name="Zr90" wo="0.43313403903" />
-    <nuclide name="Zr91" wo="0.09549277374" />
-    <nuclide name="Zr92" wo="0.14759527104" />
-    <nuclide name="Zr94" wo="0.15280552077" />
-    <nuclide name="Zr96" wo="0.02511169542" />
-    <sab name="c_H_in_H2O" />
-  </material>
-  <material id="12" name="Bottom of fuel assemblies">
-    <density units="g/cm3" value="1.762" />
-    <nuclide name="H1" wo="0.0292856" />
-    <nuclide name="O16" wo="0.2323919" />
-    <nuclide name="B10" wo="9.44159e-05" />
-    <nuclide name="B11" wo="0.00043012" />
-    <nuclide name="Zr90" wo="0.3741373658" />
-    <nuclide name="Zr91" wo="0.0824858164" />
-    <nuclide name="Zr92" wo="0.1274914944" />
-    <nuclide name="Zr94" wo="0.1319920622" />
-    <nuclide name="Zr96" wo="0.0216912612" />
-    <sab name="c_H_in_H2O" />
+  <material id="2">
+    <density units="g/cm3" value="1.0" />
+    <nuclide ao="1.0" name="Zr90" />
   </material>
 </materials>
 <?xml version='1.0' encoding='utf-8'?>
 <settings>
   <run_mode>eigenvalue</run_mode>
-  <particles>100</particles>
-  <batches>10</batches>
-  <inactive>5</inactive>
-  <source strength="1.0">
-    <space type="box">
-      <parameters>-160 -160 -183 160 160 183</parameters>
-    </space>
-  </source>
+  <particles>1000</particles>
+  <batches>5</batches>
+  <inactive>0</inactive>
 </settings>
 <?xml version='1.0' encoding='utf-8'?>
 <tallies>
   <mesh id="1">
     <dimension>17</dimension>
-    <lower_left>-182.07</lower_left>
-    <upper_right>182.07</upper_right>
+    <lower_left>-10.0</lower_left>
+    <upper_right>10.0</upper_right>
   </mesh>
   <mesh id="2">
     <dimension>17 17</dimension>
-    <lower_left>-182.07 -182.07</lower_left>
-    <upper_right>182.07 182.07</upper_right>
+    <lower_left>-10.0 -10.0</lower_left>
+    <upper_right>10.0 10.0</upper_right>
   </mesh>
   <mesh id="3">
     <dimension>17 17 17</dimension>
-    <lower_left>-182.07 -182.07 -183.0</lower_left>
-    <upper_right>182.07 182.07 183.0</upper_right>
+    <lower_left>-10.0 -10.0 -183.0</lower_left>
+    <upper_right>10.0 10.0 183.0</upper_right>
   </mesh>
   <mesh id="4" type="rectilinear">
-    <x_grid>-182.07 -160.65 -139.23 -117.81 -96.39 -74.97 -53.55000000000001 -32.129999999999995 -10.710000000000008 10.70999999999998 32.129999999999995 53.54999999999998 74.96999999999997 96.38999999999999 117.81 139.22999999999996 160.64999999999998 182.07</x_grid>
-    <y_grid>-182.07 -160.65 -139.23 -117.81 -96.39 -74.97 -53.55000000000001 -32.129999999999995 -10.710000000000008 10.70999999999998 32.129999999999995 53.54999999999998 74.96999999999997 96.38999999999999 117.81 139.22999999999996 160.64999999999998 182.07</y_grid>
+    <x_grid>-10.0 -8.823529411764707 -7.647058823529411 -6.470588235294118 -5.294117647058823 -4.117647058823529 -2.9411764705882355 -1.7647058823529402 -0.5882352941176467 0.5882352941176467 1.764705882352942 2.9411764705882355 4.117647058823529 5.294117647058824 6.4705882352941195 7.647058823529413 8.823529411764707 10.0</x_grid>
+    <y_grid>-10.0 -8.823529411764707 -7.647058823529411 -6.470588235294118 -5.294117647058823 -4.117647058823529 -2.9411764705882355 -1.7647058823529402 -0.5882352941176467 0.5882352941176467 1.764705882352942 2.9411764705882355 4.117647058823529 5.294117647058824 6.4705882352941195 7.647058823529413 8.823529411764707 10.0</y_grid>
     <z_grid>1.0 1.683624003879018 2.8345897864376153 4.772383405596668 8.034899257376447 13.52774925846868 22.77564337001445 38.34561988154435 64.55960607618856 108.69410247084474 182.99999999999991</z_grid>
   </mesh>
   <filter id="1" type="mesh">
diff --git a/tests/regression_tests/filter_mesh/results_true.dat b/tests/regression_tests/filter_mesh/results_true.dat
index 05efffe2f..55653d1a5 100644
--- a/tests/regression_tests/filter_mesh/results_true.dat
+++ b/tests/regression_tests/filter_mesh/results_true.dat
@@ -1 +1 @@
-35f04a6f062ef64116ef4eb0e9b803cd44cff7e185e2b53c9174afad8a26ca1a436ca9b800d6a228e006a9129f4536d7dce289d7a11cd56c6949d71d6a201b31
\ No newline at end of file
+2bc8fce4a61bc431e90c44400ac626e7043144b575eeb5ca66b8c4fefb9bed076b20663d096801dca63085f090a96e662f12b6281c85c3ba8ce73efbc55356ba
\ No newline at end of file
diff --git a/tests/regression_tests/filter_mesh/test.py b/tests/regression_tests/filter_mesh/test.py
index ed2e9b35b..e68c5f0e1 100644
--- a/tests/regression_tests/filter_mesh/test.py
+++ b/tests/regression_tests/filter_mesh/test.py
@@ -1,87 +1,110 @@
 import numpy as np
 
 import openmc
+import pytest
 
 from tests.testing_harness import HashedPyAPITestHarness
 
 
-class FilterMeshTestHarness(HashedPyAPITestHarness):
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
+@pytest.fixture
+def model():
+    model = openmc.model.Model()
 
-        # Initialize Meshes
-        mesh_1d = openmc.RegularMesh(mesh_id=1)
-        mesh_1d.dimension = [17]
-        mesh_1d.lower_left = [-182.07]
-        mesh_1d.upper_right = [182.07]
+    fuel = openmc.Material()
+    fuel.set_density('g/cm3', 10.0)
+    fuel.add_nuclide('U235', 1.0)
+    zr = openmc.Material()
+    zr.set_density('g/cm3', 1.0)
+    zr.add_nuclide('Zr90', 1.0)
+    model.materials.extend([fuel, zr])
 
-        mesh_2d = openmc.RegularMesh(mesh_id=2)
-        mesh_2d.dimension = [17, 17]
-        mesh_2d.lower_left = [-182.07, -182.07]
-        mesh_2d.upper_right = [182.07, 182.07]
+    box1 = openmc.model.rectangular_prism(10.0, 10.0)
+    box2 = openmc.model.rectangular_prism(20.0, 20.0, boundary_type='reflective')
+    top = openmc.ZPlane(z0=10.0, boundary_type='vacuum')
+    bottom = openmc.ZPlane(z0=-10.0, boundary_type='vacuum')
+    cell1 = openmc.Cell(fill=fuel, region=box1 & +bottom & -top)
+    cell2 = openmc.Cell(fill=zr, region=~box1 & box2 & +bottom & -top)
+    model.geometry = openmc.Geometry([cell1, cell2])
 
-        mesh_3d = openmc.RegularMesh(mesh_id=3)
-        mesh_3d.dimension = [17, 17, 17]
-        mesh_3d.lower_left = [-182.07, -182.07, -183.00]
-        mesh_3d.upper_right = [182.07, 182.07, 183.00]
+    model.settings.batches = 5
+    model.settings.inactive = 0
+    model.settings.particles = 1000
 
-        recti_mesh = openmc.RectilinearMesh(mesh_id=4)
-        recti_mesh.x_grid = np.linspace(-182.07, 182.07, 18)
-        recti_mesh.y_grid = np.linspace(-182.07, 182.07, 18)
-        recti_mesh.z_grid = np.logspace(0, np.log10(183), 11)
+    # Initialize Meshes
+    mesh_1d = openmc.RegularMesh()
+    mesh_1d.dimension = [17]
+    mesh_1d.lower_left = [-10.0]
+    mesh_1d.upper_right = [10.0]
 
-        # Initialize the filters
-        mesh_1d_filter = openmc.MeshFilter(mesh_1d)
-        mesh_2d_filter = openmc.MeshFilter(mesh_2d)
-        mesh_3d_filter = openmc.MeshFilter(mesh_3d)
-        recti_mesh_filter = openmc.MeshFilter(recti_mesh)
-        meshsurf_1d_filter = openmc.MeshSurfaceFilter(mesh_1d)
-        meshsurf_2d_filter = openmc.MeshSurfaceFilter(mesh_2d)
-        meshsurf_3d_filter = openmc.MeshSurfaceFilter(mesh_3d)
-        recti_meshsurf_filter = openmc.MeshSurfaceFilter(recti_mesh)
+    mesh_2d = openmc.RegularMesh()
+    mesh_2d.dimension = [17, 17]
+    mesh_2d.lower_left = [-10.0, -10.0]
+    mesh_2d.upper_right = [10.0, 10.0]
 
-        # Initialized the tallies
-        tally = openmc.Tally(name='tally 1')
-        tally.filters = [mesh_1d_filter]
-        tally.scores = ['total']
-        self._model.tallies.append(tally)
+    mesh_3d = openmc.RegularMesh()
+    mesh_3d.dimension = [17, 17, 17]
+    mesh_3d.lower_left = [-10.0, -10.0, -183.00]
+    mesh_3d.upper_right = [10.0, 10.0, 183.00]
 
-        tally = openmc.Tally(name='tally 2')
-        tally.filters = [meshsurf_1d_filter]
-        tally.scores = ['current']
-        self._model.tallies.append(tally)
+    recti_mesh = openmc.RectilinearMesh()
+    recti_mesh.x_grid = np.linspace(-10.0, 10.0, 18)
+    recti_mesh.y_grid = np.linspace(-10.0, 10.0, 18)
+    recti_mesh.z_grid = np.logspace(0, np.log10(183), 11)
 
-        tally = openmc.Tally(name='tally 3')
-        tally.filters = [mesh_2d_filter]
-        tally.scores = ['total']
-        self._model.tallies.append(tally)
+    # Initialize the filters
+    mesh_1d_filter = openmc.MeshFilter(mesh_1d)
+    mesh_2d_filter = openmc.MeshFilter(mesh_2d)
+    mesh_3d_filter = openmc.MeshFilter(mesh_3d)
+    recti_mesh_filter = openmc.MeshFilter(recti_mesh)
+    meshsurf_1d_filter = openmc.MeshSurfaceFilter(mesh_1d)
+    meshsurf_2d_filter = openmc.MeshSurfaceFilter(mesh_2d)
+    meshsurf_3d_filter = openmc.MeshSurfaceFilter(mesh_3d)
+    recti_meshsurf_filter = openmc.MeshSurfaceFilter(recti_mesh)
 
-        tally = openmc.Tally(name='tally 4')
-        tally.filters = [meshsurf_2d_filter]
-        tally.scores = ['current']
-        self._model.tallies.append(tally)
+    # Initialized the tallies
+    tally = openmc.Tally(name='tally 1')
+    tally.filters = [mesh_1d_filter]
+    tally.scores = ['total']
+    model.tallies.append(tally)
 
-        tally = openmc.Tally(name='tally 5')
-        tally.filters = [mesh_3d_filter]
-        tally.scores = ['total']
-        self._model.tallies.append(tally)
+    tally = openmc.Tally(name='tally 2')
+    tally.filters = [meshsurf_1d_filter]
+    tally.scores = ['current']
+    model.tallies.append(tally)
 
-        tally = openmc.Tally(name='tally 6')
-        tally.filters = [meshsurf_3d_filter]
-        tally.scores = ['current']
-        self._model.tallies.append(tally)
+    tally = openmc.Tally(name='tally 3')
+    tally.filters = [mesh_2d_filter]
+    tally.scores = ['total']
+    model.tallies.append(tally)
 
-        tally = openmc.Tally(name='tally 7')
-        tally.filters = [recti_mesh_filter]
-        tally.scores = ['total']
-        self._model.tallies.append(tally)
+    tally = openmc.Tally(name='tally 4')
+    tally.filters = [meshsurf_2d_filter]
+    tally.scores = ['current']
+    model.tallies.append(tally)
 
-        tally = openmc.Tally(name='tally 8')
-        tally.filters = [recti_meshsurf_filter]
-        tally.scores = ['current']
-        self._model.tallies.append(tally)
+    tally = openmc.Tally(name='tally 5')
+    tally.filters = [mesh_3d_filter]
+    tally.scores = ['total']
+    model.tallies.append(tally)
+
+    tally = openmc.Tally(name='tally 6')
+    tally.filters = [meshsurf_3d_filter]
+    tally.scores = ['current']
+    model.tallies.append(tally)
+
+    tally = openmc.Tally(name='tally 7')
+    tally.filters = [recti_mesh_filter]
+    tally.scores = ['total']
+    model.tallies.append(tally)
+
+    tally = openmc.Tally(name='tally 8')
+    tally.filters = [recti_meshsurf_filter]
+    tally.scores = ['current']
+    model.tallies.append(tally)
+
+    return model
 
 
-def test_filter_mesh():
-    harness = FilterMeshTestHarness('statepoint.10.h5')
+def test_filter_mesh(model):
+    harness = HashedPyAPITestHarness('statepoint.5.h5', model)
     harness.main()