FIX: expose renderer.figure and reuse a passed-in scene [circle full]

The tutorials that build a renderer themselves reach for renderer.figure,
which the pyvista backend exposes alongside scene(). Honour a fig argument
too, so plot_alignment and plot_dipole_locations composite into one scene
instead of opening a second one.

Author: natinew77-creator

doc/sphinxext/jupyterlite_lite_renderer.py

@@ -90,6 +90,15 @@ def __init__(self, *args, **kwargs):
         import pyvista_js as _pv
         self._np = _np
         self._pv = _pv
+        # plot_alignment(fig=...) and plot_dipole_locations(fig=...) composite
+        # into a scene the notebook already made, so draw into that plotter
+        # rather than opening a second one and splitting the picture in two.
+        # plot_alignment passes it positionally and create_3d_figure by name,
+        # and `fig` is _PyVistaRenderer's first argument, so accept both.
+        _fig = args[0] if args else kwargs.get("fig", None)
+        if _fig is not None and hasattr(_fig, "add_mesh"):
+            self.plotter = _fig
+            return
         self.plotter = _pv.Plotter()
         import weakref as _weakref
         _lite_live_plotters.append(_weakref.ref(self.plotter))
@@ -468,6 +477,17 @@ def set_camera(self, azimuth=None, elevation=None, distance=None,
         # views and otherwise leave the default.
         return _lite_set_view(self.plotter, azimuth)
 
+    @property
+    def figure(self):
+        """The scene, under the name the tutorials reach for.
+
+        ``_PyVistaRenderer`` hands out one object as both ``.figure`` and
+        ``.scene()``; ``20_source_alignment`` builds a renderer itself with
+        ``create_3d_figure(scene=False)`` and then passes ``renderer.figure``
+        to ``set_3d_view``, so the two have to stay the same thing here too.
+        """
+        return self.plotter
+
     def scene(self):
         return self.plotter