new: max_opacity for TF controls, see #26

ipyvolume/pylab.py

@@ -437,7 +437,7 @@ def gcc():
     return current.container
 
 
-def transfer_function(level=[0.1, 0.5, 0.9], opacity=[0.01, 0.05, 0.1], level_width=0.1, controls=True):
+def transfer_function(level=[0.1, 0.5, 0.9], opacity=[0.01, 0.05, 0.1], level_width=0.1, controls=True, max_opacity=0.2):
     """Create a transfer function, see volshow"""
     tf_kwargs = {}
     # level, opacity and widths can be scalars
@@ -472,7 +472,7 @@ def transfer_function(level=[0.1, 0.5, 0.9], opacity=[0.01, 0.05, 0.1], level_wi
     tf = ipv.TransferFunctionWidgetJs3(**tf_kwargs)
     fig = gcf()
     if controls:
-        current.container.children = (tf.control(),) + current.container.children
+        current.container.children = (tf.control(max_opacity=max_opacity),) + current.container.children
     return tf
 
 def plot_isosurface(data, level=None, color=default_color, wireframe=True, surface=True, controls=True):
@@ -509,7 +509,7 @@ def volshow(data, lighting=False, data_min=None, data_max=None, tf=None, stereo=
             specular_coefficient=0.5, specular_exponent=5,
             downscale=1,
             level=[0.1, 0.5, 0.9], opacity=[0.01, 0.05, 0.1], level_width=0.1,
-            controls=True):
+            controls=True, max_opacity=0.2):
     """Visualize a 3d array using volume rendering.
 
     Currently only 1 volume can be rendered.
@@ -530,11 +530,12 @@ def volshow(data, lighting=False, data_min=None, data_max=None, tf=None, stereo=
     :param opacity: opacity(ies) for each level, scalar or sequence of max length 3
     :param level_width: width of the (gaussian) bumps where the opacity peaks, scalar or sequence of max length 3
     :param controls: add controls for lighting and transfer function or not
+    :param max_opacity: maximum opacity for transfer function controls
     :return:
     """
     vol = gcf()
     if tf is None:
-        tf = vol.tf or transfer_function(level, opacity, level_width, controls=controls)
+        tf = vol.tf or transfer_function(level, opacity, level_width, controls=controls, max_opacity=max_opacity)
     if data_min is None:
         data_min = np.nanmin(data)
     if data_max is None:

ipyvolume/transferfunction.py

@@ -45,15 +45,15 @@ class TransferFunctionJsBumps(TransferFunction):
 	widths = traitlets.List(traitlets.CFloat, default_value=[0.1, 0.1, 0.1]).tag(sync=True)
 
 
-	def control(self):
+	def control(self, max_opacity=0.2):
 		import ipywidgets
 		return ipywidgets.VBox()
 		l1 = ipywidgets.FloatSlider(min=0, max=1, step=0.001, value=self.level1)
 		l2 = ipywidgets.FloatSlider(min=0, max=1, step=0.001, value=self.level2)
 		l3 = ipywidgets.FloatSlider(min=0, max=1, step=0.001, value=self.level3)
-		o1 = ipywidgets.FloatSlider(min=0, max=.2, step=0.001, value=self.opacity1)
-		o2 = ipywidgets.FloatSlider(min=0, max=.2, step=0.001, value=self.opacity2)
-		o3 = ipywidgets.FloatSlider(min=0, max=.2, step=0.001, value=self.opacity2)
+		o1 = ipywidgets.FloatSlider(min=0, max=max_opacity, step=0.001, value=self.opacity1)
+		o2 = ipywidgets.FloatSlider(min=0, max=max_opacity, step=0.001, value=self.opacity2)
+		o3 = ipywidgets.FloatSlider(min=0, max=max_opacity, step=0.001, value=self.opacity2)
 		ipywidgets.jslink((self, 'level1'), (l1, 'value'))
 		ipywidgets.jslink((self, 'level2'), (l2, 'value'))
 		ipywidgets.jslink((self, 'level3'), (l3, 'value'))
@@ -80,14 +80,14 @@ class TransferFunctionWidgetJs3(TransferFunction):
 	width3 = traitlets.Float(0.1).tag(sync=True)
 
 
-	def control(self):
+	def control(self, max_opacity=0.2):
 		import ipywidgets
 		l1 = ipywidgets.FloatSlider(min=0, max=1, step=0.001, value=self.level1)
 		l2 = ipywidgets.FloatSlider(min=0, max=1, step=0.001, value=self.level2)
 		l3 = ipywidgets.FloatSlider(min=0, max=1, step=0.001, value=self.level3)
-		o1 = ipywidgets.FloatSlider(min=0, max=.2, step=0.001, value=self.opacity1)
-		o2 = ipywidgets.FloatSlider(min=0, max=.2, step=0.001, value=self.opacity2)
-		o3 = ipywidgets.FloatSlider(min=0, max=.2, step=0.001, value=self.opacity2)
+		o1 = ipywidgets.FloatSlider(min=0, max=max_opacity, step=0.001, value=self.opacity1)
+		o2 = ipywidgets.FloatSlider(min=0, max=max_opacity, step=0.001, value=self.opacity2)
+		o3 = ipywidgets.FloatSlider(min=0, max=max_opacity, step=0.001, value=self.opacity2)
 		ipywidgets.jslink((self, 'level1'), (l1, 'value'))
 		ipywidgets.jslink((self, 'level2'), (l2, 'value'))
 		ipywidgets.jslink((self, 'level3'), (l3, 'value'))
@@ -144,14 +144,14 @@ def recompute_rgba(self, *_ignore):
 		self.rgba = rgba
 		#self._notify_trait("rgba", old_value, self.rgba)
 
-	def control(self):
+	def control(self, max_opacity=0.2):
 		import ipywidgets
 		l1 = ipywidgets.FloatSlider(min=0, max=1, value=self.level1)
 		l2 = ipywidgets.FloatSlider(min=0, max=1, value=self.level2)
 		l3 = ipywidgets.FloatSlider(min=0, max=1, value=self.level3)
-		o1 = ipywidgets.FloatSlider(min=0, max=0.2, step=0.001, value=self.opacity1)
-		o2 = ipywidgets.FloatSlider(min=0, max=0.2, step=0.001, value=self.opacity2)
-		o3 = ipywidgets.FloatSlider(min=0, max=0.2, step=0.001, value=self.opacity2)
+		o1 = ipywidgets.FloatSlider(min=0, max=max_opacity, step=0.001, value=self.opacity1)
+		o2 = ipywidgets.FloatSlider(min=0, max=max_opacity, step=0.001, value=self.opacity2)
+		o3 = ipywidgets.FloatSlider(min=0, max=max_opacity, step=0.001, value=self.opacity2)
 		ipywidgets.jslink((self, 'level1'), (l1, 'value'))
 		ipywidgets.jslink((self, 'level2'), (l2, 'value'))
 		ipywidgets.jslink((self, 'level3'), (l3, 'value'))