MRG: Add reset_camera() primitive in _Renderer

mne/viz/_brain/_brain.py

@@ -775,6 +775,7 @@ def show_view(self, view=None, roll=None, distance=None, row=0, col=0,
         self._renderer.subplot(row, col)
         self._renderer.set_camera(azimuth=view.azim,
                                   elevation=view.elev)
+        self._renderer.reset_camera()
 
     def save_image(self, filename, mode='rgb'):
         """Save view from all panels to disk.

mne/viz/backends/_pysurfer_mayavi.py

@@ -275,6 +275,11 @@ def set_camera(self, azimuth=None, elevation=None, distance=None,
                      elevation=elevation, distance=distance,
                      focalpoint=focalpoint)
 
+    def reset_camera(self):
+        renderer = getattr(self.fig.scene, 'renderer', None)
+        if renderer is not None:
+            renderer.reset_camera()
+
     def screenshot(self, mode='rgb', filename=None):
         return _take_3d_screenshot(figure=self.fig, mode=mode,
                                    filename=filename)

mne/viz/backends/_pyvista.py

@@ -426,6 +426,9 @@ def set_camera(self, azimuth=None, elevation=None, distance=None,
         _set_3d_view(self.figure, azimuth=azimuth, elevation=elevation,
                      distance=distance, focalpoint=focalpoint)
 
+    def reset_camera(self):
+        self.plotter.reset_camera()
+
     def screenshot(self, mode='rgb', filename=None):
         return _take_3d_screenshot(figure=self.figure, mode=mode,
                                    filename=filename)

mne/viz/backends/base_renderer.py

@@ -348,6 +348,11 @@ def set_camera(self, azimuth=None, elevation=None, distance=None,
         """
         pass
 
+    @abstractclassmethod
+    def reset_camera(self):
+        """Reset the camera properties."""
+        pass
+
     @abstractclassmethod
     def screenshot(self, mode='rgb', filename=None):
         """Take a screenshot of the scene.

mne/viz/backends/tests/test_renderer.py

@@ -150,4 +150,5 @@ def test_3d_backend(renderer):
     rend.set_camera(azimuth=180.0, elevation=90.0,
                     distance=cam_distance,
                     focalpoint=center)
+    rend.reset_camera()
     rend.show()