Add is used flag to material (#3854)

_unittest/test_03_Materials.py

@@ -227,7 +227,9 @@ def test_09_non_linear_materials(self, add_app):
         assert app.materials["myMat"].permittivity.type == "nonlinear"
         assert app.materials["myMat"].permeability.bunit == "tesla"
         mat2 = app.materials.add_material("myMat2")
+        assert not mat2.is_used
         assert app.modeler.create_box([0, 0, 0], [10, 10, 10], matname="myMat2")
+        assert app.materials.material_keys["mymat2"].is_used
 
     def test_10_add_material_sweep(self):
         assert self.aedtapp.materials.add_material_sweep(["copper", "aluminum"], "sweep_copper")

pyaedt/modules/Material.py

@@ -1132,6 +1132,14 @@ def __init__(self, materials, name, props=None):
             self.mod_since_lib = self._props["ModSinceLib"]
             del self._props["ModSinceLib"]
 
+    @property
+    def is_used(self):
+        """Checks if a project material is in use."""
+        is_used = self._omaterial_manager.IsUsed(self.name)
+        if is_used == 0:
+            return False
+        return True
+
     @property
     def coordinate_system(self):
         """Material coordinate system."""