ENH: Improve Endoscopy flythrough

Modules/Scripted/Endoscopy/Endoscopy.py

@@ -24,7 +24,7 @@ def __init__(self, parent):
             """
 Create or import a markups curve.
 Clicking "Create flythrough" will make a flythrough curve and enable the flythrough panel.
-You can manually scroll through the path with the Frame slider. The Play/Pause button toggles animated flythrough.
+You can manually scroll through the path with the Frame slider.  The Play/Pause button toggles animated flythrough.
 The Frame Skip slider speeds up the animation by skipping points on the path.
 The Frame Delay slider slows down the animation by adding more time between frames.
 The View Angle provides is used to approximate the optics of an endoscopy system.
@@ -123,8 +123,8 @@ def setup(self):
         self.outputPathNodeSelector.setMRMLScene(slicer.mrmlScene)
 
         # In the Endoscopy module we want mouse involvement in the 3-dimensional view to rotate the camera orientation.
-        # We want to disable the use of the mouse to do all other things in that pane.
-        # TODO: Is that what we really want?  Is this the way to do that or need we do more or different?
+        # How do we ensure that is enabled?  How do we disable all other uses of the mouse in that pane.
+        # TODO: Is that what we really want?  Is this the way to do that or need we do more, less, different?
         interactionNode = slicer.mrmlScene.GetNodeByID("vtkMRMLInteractionNodeSingleton")
         interactionNode.SwitchToViewTransformMode()
         interactionNode.SetPlaceModePersistence(0)
@@ -269,6 +269,7 @@ def setupFlythroughUI(self):
         # View angle slider
         flythroughViewAngleSlider = ctk.ctkSliderWidget()
         logging.debug("    flythroughViewAngleSlider = ctk.ctkSliderWidget()")
+        # View angles are in degrees
         flythroughViewAngleSlider.decimals = 0
         flythroughViewAngleSlider.minimum = 30
         flythroughViewAngleSlider.maximum = 180
@@ -277,8 +278,8 @@ def setupFlythroughUI(self):
             '        flythroughViewAngleSlider.connect("valueChanged(double)", '
             + "self.flythroughViewAngleSliderValueChanged)"
         )
-        flythroughFormLayout.addRow(_("View Angle:"), flythroughViewAngleSlider)
-        logging.debug('        flythroughFormLayout.addRow("View Angle:", flythroughViewAngleSlider)')
+        flythroughFormLayout.addRow(_("View Angle°:"), flythroughViewAngleSlider)
+        logging.debug('        flythroughFormLayout.addRow("View Angle°:", flythroughViewAngleSlider)')
         self.flythroughViewAngleSlider = flythroughViewAngleSlider
 
         # Play button
@@ -396,13 +397,16 @@ def setFiducialNode(self, newFiducialNode):
         self.updateWidgetFromMRML()
 
     def updateWidgetFromMRML(self):
-        # TODO: There are many other widgets and many other form fields.  Which need to be included here?
+        # TODO: There are other widgets and other form fields.  What rule determines which need to be included here?
         if self.camera:
+            # View angles are in degrees
             self.flythroughViewAngleSlider.value = self.camera.GetViewAngle()
         if self.cameraNode:
             pass
         if self.fiducialNode:
             pass
+        if self.transform:
+            pass
 
     def onCameraModified(self, observer, eventid):
         self.updateWidgetFromMRML()
@@ -411,7 +415,7 @@ def onCameraNodeModified(self, observer, eventid):
         self.updateWidgetFromMRML()
 
     def enableOrDisableCreateButton(self):
-        """Connected to both the fiducial and camera node selector. It allows to
+        """Connected to both the fiducial and camera node selector.  It allows to
         enable or disable the 'Create model' button."""
         self.createPathButton.enabled = (
             self.cameraNodeSelector.currentNode()
@@ -430,7 +434,13 @@ def onFiducialNodeModified(self, observer, eventid):
             self.logic = EndoscopyLogic(self.fiducialNode)
 
     def onCreatePathButtonClicked(self):
-        """Connected to 'Create model' button. It allows to:
+        # TODO: Don't create a model, though do create the cursor (so the user can see where in the flythrough we are)
+        #       and probably its transform (though why?).
+        # TODO: Since we are not creating a model, change the UI so that a name for the model cannot be specified, etc.
+        # TODO: Perhaps remove this button and instead invoke this functionality whenever the user selects an input
+        #       curve within the Endoscopy module.
+
+        """Connected to 'Create model' button.  It allows to:
         - compute the path
         - create the associated model"""
 
@@ -443,6 +453,7 @@ def onCreatePathButtonClicked(self):
         numberOfControlPoints = self.logic.resampledCurve.GetNumberOfControlPoints()
         logging.debug(f"-> Computed path contains {numberOfControlPoints} elements")
 
+        # TODO: Build cursor and its transform, but not this model
         logging.debug("Create model...")
         model = EndoscopyPathModel(self.logic.resampledCurve, fiducialNode, outputPathNode)
         logging.debug("-> Model created")
@@ -473,6 +484,7 @@ def flythroughFrameDelaySliderValueChanged(self, newValue):
 
     def flythroughViewAngleSliderValueChanged(self, newValue):
         if self.cameraNode:
+            # View angles are in degrees
             self.cameraNode.GetCamera().SetViewAngle(newValue)
 
     def onPlayButtonToggled(self, checked):
@@ -915,7 +927,7 @@ def __init__(self, resampledCurve, inputCurve, outputPathNode=None, cursorType=N
         :param resampledCurve: resampledCurve generated by EndoscopyLogic
         :param inputCurve: input node, just used for naming the output node.
         :param outputPathNode: output model node that stores the path points.
-        :param cursorType: can be 'markups' or 'model'. Markups has a number of advantages (radius it is easier to
+        :param cursorType: can be 'markups' or 'model'.  Markups has a number of advantages (radius it is easier to
           change the size, can jump to views by clicking on it, has more visualization options, can be scaled to fixed
           display size), but if some applications relied on having a model node as cursor then this argument can be used
           to achieve that.
@@ -940,7 +952,6 @@ def __init__(self, resampledCurve, inputCurve, outputPathNode=None, cursorType=N
         idArray.InsertNextTuple1(0)
 
         for resampledCurveControlPointIndex in range(resampledCurve.GetNumberOfControlPoints()):
-            # TODO: Rename `point` to something more informative
             point = np.zeros((3,))
             resampledCurve.GetNthControlPointPositionWorld(resampledCurveControlPointIndex, point)
             pointIndex = points.InsertNextPoint(*point)
@@ -959,7 +970,7 @@ def __init__(self, resampledCurve, inputCurve, outputPathNode=None, cursorType=N
             model.CreateDefaultDisplayNodes()
             model.GetDisplayNode().SetColor(1, 1, 0)  # yellow
 
-        model.SetAndObservePolyData(polyData)
+        model.SetAndObservePolyData(polyData)  # TODO: Restore me
 
         # Camera cursor
         cursor = model.GetNodeReference("CameraCursor")
@@ -972,6 +983,7 @@ def __init__(self, resampledCurve, inputCurve, outputPathNode=None, cursorType=N
                 cursor.CreateDefaultDisplayNodes()
                 cursor.GetDisplayNode().SetSelectedColor(1, 0, 0)  # red
                 cursor.GetDisplayNode().SetSliceProjection(True)
+                cursor.GetDisplayNode().BackfaceCullingOn()  # so that the camera can see through the cursor from inside
                 cursor.AddControlPoint(vtk.vtkVector3d(0, 0, 0), " ")  # do not show any visible label
                 cursor.SetNthControlPointLocked(0, True)
             else: