PR #20 feedback.

ensemble/volren/volume_axes.py

@@ -24,15 +24,11 @@ class VolumeAxes(ABCVolumeSceneMember):
     # ABCVolumeSceneMember interface
     #--------------------------------------------------------------------------
 
-    def add_actors_to_scene(self, scene_model):
-
-        actor = self.find_volume_actor(scene_model)
-        if actor is None:
-            return
+    def add_actors_to_scene(self, scene_model, volume_actor):
 
         # Some axes with ticks
         if any(self.visible_axis_scales):
-            bounds = actor.bounds
+            bounds = volume_actor.bounds
             x_vis, y_vis, z_vis = self.visible_axis_scales
             x_range, y_range, z_range = self.visible_axis_ranges
             cube_axes = tvtk.CubeAxesActor(

ensemble/volren/volume_bounding_box.py

@@ -12,14 +12,10 @@ class VolumeBoundingBox(ABCVolumeSceneMember):
     # ABCVolumeSceneMember interface
     #--------------------------------------------------------------------------
 
-    def add_actors_to_scene(self, scene_model):
-
-        actor = self.find_volume_actor(scene_model)
-        if actor is None:
-            return
+    def add_actors_to_scene(self, scene_model, volume_actor):
 
         # An outline of the bounds of the Volume actor's data
-        outline = tvtk.OutlineFilter(input=actor.mapper.input)
+        outline = tvtk.OutlineFilter(input=volume_actor.mapper.input)
         outline_mapper = tvtk.PolyDataMapper(input=outline.output)
         outline_actor = tvtk.Actor(mapper=outline_mapper)
         outline_actor.property.opacity = 0.3

ensemble/volren/volume_renderer.py

@@ -1,6 +1,6 @@
 from mayavi.sources.vtk_data_source import VTKDataSource
 from mayavi.tools.tools import add_dataset
-from traits.api import CInt, Instance, List
+from traits.api import CInt, Instance, List, Property
 from tvtk.api import tvtk
 
 from ensemble.ctf.piecewise import PiecewiseFunction
@@ -21,6 +21,9 @@ class VolumeRenderer(ABCVolumeSceneMember):
     # The mayavi volume renderer object
     volume = Instance(Volume3D)
 
+    # The tvtk.Actor for `volume`
+    actor = Property(Instance(tvtk.Actor), depends_on='volume')
+
     # The minimum and maximum displayed intensity values.
     vmin = CInt(0)
     vmax = CInt(255)
@@ -36,11 +39,11 @@ class VolumeRenderer(ABCVolumeSceneMember):
     # ABCVolumeSceneMember interface
     # -------------------------------------------------------------------------
 
-    def add_actors_to_scene(self, scene_model):
-        sf = add_dataset(self.data.resampled_image_data,
-                         figure=scene_model.mayavi_scene)
-        self.data_source = sf
-        self.volume = volume3d(sf, figure=scene_model.mayavi_scene)
+    def add_actors_to_scene(self, scene_model, volume_actor):
+        source = add_dataset(self.data.resampled_image_data,
+                             figure=scene_model.mayavi_scene)
+        self.data_source = source
+        self.volume = volume3d(source, figure=scene_model.mayavi_scene)
         self._setup_volume()
 
     # -------------------------------------------------------------------------
@@ -57,11 +60,11 @@ def set_transfer_function(self, colors=None, opacities=None):
         if opacities is not None:
             self.opacities = opacities
 
-        ctf = tvtk.ColorTransferFunction()
+        color_tf = tvtk.ColorTransferFunction()
         for color in self.colors.items():
-            ctf.add_rgb_point(lerp(color[0]), *(color[1:]))
+            color_tf.add_rgb_point(lerp(color[0]), *(color[1:]))
 
-        otf = tvtk.PiecewiseFunction()
+        opacity_tf = tvtk.PiecewiseFunction()
         alphas = self.opacities.items()
         for i, alpha in enumerate(alphas):
             x = alpha[0]
@@ -70,21 +73,17 @@ def set_transfer_function(self, colors=None, opacities=None):
                 # we need to jog a value that is exactly equal by a little bit.
                 if alphas[i-1][0] == alpha[0]:
                     x += 1e-8
-            otf.add_point(lerp(x), alpha[1])
+            opacity_tf.add_point(lerp(x), alpha[1])
 
-        self._set_volume_ctf(ctf, otf)
+        self._set_volume_ctf(color_tf, opacity_tf)
 
     # -------------------------------------------------------------------------
-    # Default values
+    # Traits bits
     # -------------------------------------------------------------------------
 
     def _clip_bounds_default(self):
         return [0, CLIP_MAX, 0, CLIP_MAX, 0, CLIP_MAX]
 
-    # -------------------------------------------------------------------------
-    # Traits notifications
-    # -------------------------------------------------------------------------
-
     def _data_changed(self):
         self.vmin = self.data.raw_data.min()
         self.vmax = self.data.raw_data.max()
@@ -98,6 +97,9 @@ def _data_changed(self):
     def _clip_bounds_changed(self):
         self._set_volume_clip_planes()
 
+    def _get_actor(self):
+        return self.volume.actors[0]
+
     # -------------------------------------------------------------------------
     # Private methods
     # -------------------------------------------------------------------------
@@ -120,9 +122,9 @@ def _set_volume_clip_planes(self):
         # Set them as the clipping planes for the volume mapper
         self.volume.volume.mapper.clipping_planes = planes
 
-    def _set_volume_ctf(self, ctf, otf):
+    def _set_volume_ctf(self, color_tf, opacity_tf):
         if self.volume is not None:
             vp = self.volume.volume_property
-            vp.set_scalar_opacity(otf)
-            vp.set_color(ctf)
+            vp.set_scalar_opacity(opacity_tf)
+            vp.set_color(color_tf)
             self.volume._update_ctf_fired()

ensemble/volren/volume_scene_member.py

@@ -9,20 +9,6 @@ class ABCVolumeSceneMember(ABCHasStrictTraits):
     """
 
     @abstractmethod
-    def add_actors_to_scene(self, scene_model):
+    def add_actors_to_scene(self, scene_model, volume_actor):
         """ Add actors to the mayavi scene `scene_model`.
         """
-
-    @staticmethod
-    def find_volume_actor(scene_model):
-        """ Return the first `Volume` actor found in a Mayavi `SceneModel`.
-        """
-        import tvtk  # An expensive import that should be deferred
-
-        volume_class = tvtk.tvtk_classes.volume.Volume
-
-        for actor in scene_model.actor_list:
-            if isinstance(actor, volume_class):
-                return actor
-
-        return None

ensemble/volren/volume_viewer.py

@@ -95,11 +95,12 @@ def ctf_updated(self):
     @on_trait_change('model.activated')
     def display_model(self):
         # Add the volume to the scene
-        self.volume_renderer.add_actors_to_scene(self.model)
+        self.volume_renderer.add_actors_to_scene(self.model, None)
 
         # Add the other members to the scene
+        volume_actor = self.volume_renderer.actor
         for member in self.scene_members:
-            member.add_actors_to_scene(self.model)
+            member.add_actors_to_scene(self.model, volume_actor)
 
         self._setup_camera()
         self.model.scene.background = (0, 0, 0)