From d7765cac282e1f056f5d6c58308a406a90757a83 Mon Sep 17 00:00:00 2001
From: nmannall <n.mannall@epcc.ed.ac.uk>
Date: Fri, 17 May 2024 11:43:19 +0100
Subject: [PATCH] Refactor Materials UserObject build process

---
 gprMax/cmds_multiuse.py  | 10 +++++-----
 gprMax/grid/fdtd_grid.py |  1 -
 gprMax/model.py          |  2 ++
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/gprMax/cmds_multiuse.py b/gprMax/cmds_multiuse.py
index 52672e67..3bb30f95 100644
--- a/gprMax/cmds_multiuse.py
+++ b/gprMax/cmds_multiuse.py
@@ -1256,7 +1256,7 @@ class Material(UserObjectMulti):
         self.order = 10
         self.hash = "#material"
 
-    def build(self, grid, uip):
+    def build(self, model, uip):
         try:
             er = self.kwargs["er"]
             se = self.kwargs["se"]
@@ -1289,13 +1289,13 @@ class Material(UserObjectMulti):
         if sm < 0:
             logger.exception(f"{self.params_str()} requires a positive value for magnetic loss.")
             raise ValueError
-        if any(x.ID == material_id for x in grid.materials):
+        if any(x.ID == material_id for x in model.materials):
             logger.exception(f"{self.params_str()} with ID {material_id} already exists")
             raise ValueError
 
         # Create a new instance of the Material class material
         # (start index after pec & free_space)
-        m = MaterialUser(len(grid.materials), material_id)
+        m = MaterialUser(len(model.materials), material_id)
         m.se = se
         m.mr = mr
         m.sm = sm
@@ -1306,12 +1306,12 @@ class Material(UserObjectMulti):
 
         m.er = er
         logger.info(
-            f"{self.grid_name(grid)}Material {m.ID} with eps_r={m.er:g}, "
+            f"{[model.title]} Material {m.ID} with eps_r={m.er:g}, "
             f"sigma={m.se:g} S/m; mu_r={m.mr:g}, sigma*={m.sm:g} Ohm/m "
             f"created."
         )
 
-        grid.materials.append(m)
+        model.materials.append(m)
 
 
 class AddDebyeDispersion(UserObjectMulti):
diff --git a/gprMax/grid/fdtd_grid.py b/gprMax/grid/fdtd_grid.py
index 2797a2c4..ec6bb363 100644
--- a/gprMax/grid/fdtd_grid.py
+++ b/gprMax/grid/fdtd_grid.py
@@ -76,7 +76,6 @@ class FDTDGrid:
         # TODO: Add type information.
         # Currently importing GeometryObjects, GeometryView, and
         # SubGridBaseGrid cause cyclic dependencies
-        self.materials: List[Material] = []
         self.mixingmodels = []
         self.averagevolumeobjects = True
         self.fractalvolumes = []
diff --git a/gprMax/model.py b/gprMax/model.py
index a2abec3d..07f9f10e 100644
--- a/gprMax/model.py
+++ b/gprMax/model.py
@@ -28,6 +28,7 @@ from colorama import Fore, Style, init
 
 from gprMax.grid.cuda_grid import CUDAGrid
 from gprMax.grid.opencl_grid import OpenCLGrid
+from gprMax.materials import Material
 from gprMax.subgrids.grid import SubGridBaseGrid
 
 init()
@@ -64,6 +65,7 @@ class Model:
 
         self.G = self._create_grid()
         self.subgrids: List[SubGridBaseGrid] = []
+        self.materials: List[Material] = []
 
         # Monitor memory usage
         self.p = None