MNT: only try to update the colormap if we have something to update

tacaswell · tacaswell · commit 68d3dbdb538c · 2020-11-10T17:27:56.000-05:00
diff --git a/lib/mpl_toolkits/mplot3d/art3d.py b/lib/mpl_toolkits/mplot3d/art3d.py
@@ -639,6 +639,9 @@ def do_3d_projection(self, renderer=None):
 
 
 def _update_scalarmappable(sm):
+    if sm._A is None:
+        return
+
     copy_state = sm._update_dict['array']
     ret = sm.update_scalarmappable()
     if copy_state:
