Merge pull request #2111 from shimwell/adding_dagmc_bounding_box_property

adding bounding box property to DAGMCUniverse objects

openmc/universe.py

@@ -7,6 +7,7 @@ from pathlib import Path
 from tempfile import TemporaryDirectory
 from xml.etree import ElementTree as ET
 
+import h5py
 import numpy as np
 
 import openmc
@@ -630,6 +631,9 @@ class DAGMCUniverse(UniverseBase):
     auto_mat_ids : bool
         Set IDs automatically on initialization (True)  or report overlaps
         in ID space between OpenMC and UWUW materials (False)
+    bounding_box : 2-tuple of numpy.array
+        Lower-left and upper-right coordinates of an axis-aligned bounding box
+        of the universe.
     """
 
     def __init__(self,
@@ -650,6 +654,14 @@ class DAGMCUniverse(UniverseBase):
         string += '{: <16}=\t{}\n'.format('\tFile', self.filename)
         return string
 
+    @property
+    def bounding_box(self):
+        with h5py.File(self.filename) as dagmc_file:
+            coords = dagmc_file['tstt']['nodes']['coordinates'][()]
+            lower_left_corner = coords.min(axis=0)
+            upper_right_corner = coords.max(axis=0)
+            return (lower_left_corner, upper_right_corner)
+
     @property
     def filename(self):
         return self._filename

tests/regression_tests/dagmc/universes/test.py

@@ -46,6 +46,11 @@ class DAGMCUniverseTest(PyAPITestHarness):
         # create the DAGMC universe
         pincell_univ = openmc.DAGMCUniverse(filename='dagmc.h5m', auto_geom_ids=True)
 
+        # checks that the bounding box is calculated correctly
+        bounding_box = pincell_univ.bounding_box
+        assert bounding_box[0].tolist() == [-25., -25., -25.]
+        assert bounding_box[1].tolist() == [25., 25., 25.]
+
         # create a 2 x 2 lattice using the DAGMC pincell
         pitch = np.asarray((24.0, 24.0))
         lattice = openmc.RectLattice()