hold the bc settings per plotter instance

doc/changelog.d/3897.miscellaneous.md

@@ -0,0 +1 @@
+hold the bc settings per plotter instance

src/ansys/mapdl/core/plotting/visualizer.py

@@ -51,16 +51,13 @@
 
 def _first_use():
     # Run first time we use the visualizer
-    global BC_plot_settings
     global _FIRST_USE_RUN
     if _FIRST_USE_RUN is True:
         return
     if _HAS_VISUALIZER:
-        from ansys.mapdl.core.plotting.plotting_defaults import DefaultSymbol
         from ansys.mapdl.core.plotting.theme import _apply_default_theme
 
         _apply_default_theme()
-        BC_plot_settings = DefaultSymbol()
     _FIRST_USE_RUN = True
 
 
@@ -138,6 +135,18 @@ def __init__(
         self._notebook = None
         self._savefig = None
         self._title = None
+        self._bc_settings = None
+
+    @property
+    def bc_settings(self):
+        if self._bc_settings is None:
+            self._make_bc_settings()
+        return self._bc_settings
+
+    def _make_bc_settings(self):
+        from ansys.mapdl.core.plotting.plotting_defaults import DefaultSymbol
+
+        self._bc_settings = DefaultSymbol()
 
     def _bc_labels_checker(self, bc_labels):
         """Make sure we have allowed parameters and data types for ``bc_labels``"""
@@ -601,13 +610,13 @@ def bc_nodes_plot(
                 orient=False,
                 scale="scale",
                 # tolerance=0.05,
-                geom=BC_plot_settings(each_label)["glyph"],
+                geom=self.bc_settings(each_label)["glyph"],
             )
             name_ = f"{each_label}"
             self.scene.add_mesh(
                 glyphs,
                 # name_filter=None,
-                color=BC_plot_settings(each_label)["color"],
+                color=self.bc_settings(each_label)["color"],
                 style="surface",
                 # style='wireframe',
                 # line_width=3,
@@ -658,11 +667,11 @@ def bc_nodes_plot(
                     # something it can be seen properly in the legend
                     label_ = value[1]
                     if "U" in label_:
-                        value = [BC_plot_settings("UY")["glyph"], label_, value[2]]
+                        value = [self.bc_settings("UY")["glyph"], label_, value[2]]
                     elif "F" in label_:
-                        value = [BC_plot_settings("FX")["glyph"], label_, value[2]]
+                        value = [self.bc_settings("FX")["glyph"], label_, value[2]]
                     else:
-                        value = [BC_plot_settings(label_)["glyph"], label_, value[2]]
+                        value = [self.bc_settings(label_)["glyph"], label_, value[2]]
 
                     if symbol == value[1]:
                         sorted_dict[key] = value