FIX: MIP is much better

mne/viz/_brain/_brain.py

@@ -579,6 +579,8 @@ def remove_labels(self):
     def add_volume(self, stc_vol, src_vol, trans):
         from ...utils import Bunch
         from ...source_estimate import VolVectorSourceEstimate
+        import pyvista as pv
+        from matplotlib.colors import ListedColormap
         assert isinstance(stc_vol, VolVectorSourceEstimate)
         assert src_vol.kind == 'volume'
         use = src_vol[0]
@@ -605,7 +607,6 @@ def add_volume(self, stc_vol, src_vol, trans):
         src_mri_t = use['src_mri_t']['trans'].copy()
         src_mri_t[:3] *= mult
         assert np.allclose(src_mri_t[:3, :3], np.diag([src_mri_t[0, 0]] * 3))
-        import pyvista as pv
         grid = pv.UniformGrid()
         grid.dimensions = n_pts + 1  # inject data on the cells
         origin = src_mri_t[:3, 3]
@@ -618,7 +619,9 @@ def add_volume(self, stc_vol, src_vol, trans):
         scalars[self._data[hemi]['vertices']] = subvals
         grid.cell_arrays['values'] = scalars
         self._data[hemi]['grid_actor'] = self._renderer.plotter.add_volume(
-            grid)
+            grid, mapper='gpu', blending='maximum', culling='back',
+            show_scalar_bar=False, clim=self._cmap_range,
+            cmap=ListedColormap(self._data['ctable'] / 255.))
         self._data[hemi]['grid'] = grid
 
         self.set_time_interpolation(self.time_interpolation)
@@ -1091,6 +1094,10 @@ def update_lut(self, fmin=None, fmid=None, fmax=None):
                     else:
                         scalar_bar = None
                     _set_colormap_range(actor, ctable, scalar_bar, rng)
+                # XXX add here
+                # grid_actor = hemi_data.get('grid_actor')
+                # if grid_actor is not None:
+                #     _set_colormap_range(grid_actor, ctable, None, rng)
                 glyph_actor = hemi_data.get('glyph_actor')
                 if glyph_actor is not None:
                     _set_colormap_range(glyph_actor, ctable, None, rng)