Experts,

This is just getting to the point where it is dragging me down mentally. I hate being stuck on something long after I've 'paid my dues' (searched & tried way more than I should have to on a single issue)...

It is actually simple:

-Do what the OnMouseDown() does i the Flights Demo, but programmatically.

Private Overloads Sub OnMouseDown(ByVal sender As Object, ByVal e As MouseButtonEventArgs)
Dim ftv = New ConnectionVisual3D(Me, ConnectionPoints(0), ConnectionPoints(1))
ftv.MyOpacity = 1.0
view1.Children.Add(ftv)

2014-07-18 EDIT:

I neglected to show how I am calling my child WPF window (the Flight Demo). This is probably important:

Private Sub mnuDisplay_DisplayEarth_click(sender As Object, e As RoutedEventArgs)
            Dim wpfEarth As New TheEarthWindow(Me)
            wpfEarth.Show()
            Dim newWindowThread As New Thread(New ThreadStart(Sub()
                                                                  Dim tempWindow As New TheEarthWindow(Me)
                                                                  AddHandler tempWindow.Closed, Sub(s2, e2) Dispatcher.CurrentDispatcher.BeginInvokeShutdown(DispatcherPriority.Background)
                                                                  tempWindow.Show()
                                                                  System.Windows.Threading.Dispatcher.Run()
                                                              End Sub))
            ' required for WPF:
            newWindowThread.SetApartmentState(ApartmentState.STA)
            ' Make the thread a background thread
            newWindowThread.IsBackground = True
            ' Start the thread
            newWindowThread.Start()

Q: I tried DOZENS of ways to open up a child WPF window, and this was the best I could do. How does spawning a child WPF Window like this impact addressing and adding children in the child window (I called the Flight Demo window "TheEarthWindow" here)?

TIA!

ORIGINAL POST FOLLOWS

I have the main thread watching a MSMQ, which feeds it 'connections'. Al lthis is fine. The problem comes when I go to add the 'connecction' to the 'earth', and I get either:

1. The dread "The calling thread cannot access this object because a different thread owns it."
2. Or the less frequent "This API was accessed with arguments from the wrong context."
   

...no matter WHAT I try... I have even gone as far as creating events & delegates, adding connections to the ObservableCollection, creating my own OCs, and every manner of delegates, invokes, and Dispatchers.

I have even tried creating my own ItemsControl in XAML, but I can't figure out how to code it for the tubes (no intellisense accepts it), or where in the 'tree' to place the following:

        <ItemsControl ItemsSource="{Binding Flights}">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                        <Viewport3D /> <---???
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </ItemsControl>

Here is how I last was configured to

    Private Sub AddTheConnection(sender As Object, e As EventArgs)
        Try
            Me.childConn.MyOpacity = 1.0
            TheEarthSphere.Children.Add(childConn)
            Me.Connections.Add(childConn) ' for reference so they can be removed later...
        Catch ex As Exception
            Dim m As String = "AddTheConnection"
            log.Fatal(m & "() Exception.Message(): " & ex.Message)
            log.Fatal(m & "() Exception.ToString(): " & ex.ToString)
            log.Fatal(m & "() Exception.StackTrace(): " & ex.StackTrace)
        End Try
    End Sub

This was called any number of ways, and some attempts were without an event signature on the methods. Here is a commented summary of failures:

 ' this crashed App.run:
        'If Not Application.Current.Dispatcher.CheckAccess() Then
        '    Application.Current.Dispatcher.Invoke(New MyFunctionDelegate(AddressOf AddChildToScene))
        '    Return ' Important to leave the culprit thread
        'End If
        '=========================================================================
        ' this:
        'Me.TheEarthSphere.Children.Add(childObject)
        'TheEarthSphere.Children.Add(childObject)
        ' yields: The calling thread cannot access this object because a different thread owns it.
        '=========================================================================
        ' this:
        'Me.Dispatcher.Invoke(Sub()
        '                         TheEarthSphere.Children.Add(childObject)
        '                     End Sub)
        '' yields: This API was accessed with arguments from the wrong context.
        '=========================================================================
        ' this:
        ' MyBase.AddChild(childObject)
        ' yields: The calling thread cannot access this object because a different thread owns it.
        '=========================================================================
        ' this:
        ' Me.AddChild(childObject)
        ' yields: The calling thread cannot access this object because a different thread owns it.
        '=========================================================================
        ' this:
        'stackPanel.Dispatcher.BeginInvoke(DispatcherPriority.Normal, Sub() stackPanel.Children.Add(New TextBlock With {.Text = text})))
        'TheEarthSphere.Dispatcher.BeginInvoke(Sub()
        '                                          TheEarthSphere.Children.Add(childObject)
        '                                      End Sub)
        ' yields: Exception has been thrown by the target of an invocation.
        ' from this line in Firsty: System.Windows.Threading.Dispatcher.Run()
        '=========================================================================
        ' this:
        'Me.view1.Children.Add(childObject)
        ' yields: The calling thread cannot access this object because a different thread owns it.
        '=========================================================================
        ' this:
        'Me.view1.Dispatcher.Invoke(Sub()
        '                               view1.Children.Add(childObject)
        '                           End Sub)
        ' yields: This API was accessed with arguments from the wrong context.
        '=========================================================================
        ' this:
        ' Application.Current.Dispatcher.Invoke(New Action(Sub()
        'Me.Dispatcher.Invoke(New Action(Sub()
        '                                    TheEarthSphere.Children.Add(childObject)
        '                                End Sub))
        ' yields: The calling thread cannot access this object because a different thread owns it.
        '=========================================================================
        'Me.view1.Dispatcher.Invoke(New Action(Sub()
        '                                          'TheEarthSphere.Children.Add(childConn)
        '                                          Me.Conns.Add(childConn)
        '                                      End Sub))
        ' yields: The calling thread cannot access this object because a different thread owns it.
        '=========================================================================
        ' this:
        'Me.Dispatcher.Invoke(New Action(Sub()
        '                                    Me.Conns.Add(childConn)
        '                                End Sub))
        ' yields:
        '=========================================================================
        ' an event to allow thread communication?

        'RaiseEvent ConnectionAdded(Me, EventArgs.Empty)

        '=========================================================================

tried view1.Children.Add(childConn) and got: The calling thread cannot access this object because a different thread owns it.

Seriously, what am I going to have to do to get past this and move on?

Yours in desperation...

pat
:(

Experts,

Maybe I can get some help with this problem.

I have the Flights Demo code running fine in a WPF window-as long as that window is the "Startup URI" in my project's Properties -> Application -> Statup URI. It responds to mouse & keyboard as expected.

BUT, when I call that same class from code as a child of a parent WPF window, the child displays fine-and even animates-but is completely unresponsive to mouse & keyboard (except to close the window itself.

Now here is the weird part/hint that might tell the right person what the issue is:

When I close the child WPF window by clicking the close("x") widget, the window goes away, but I can see it still generating log entries!

Figuring on a thread-centric need, I have tried the following with no change in symptoms:

A. Just call it:

Dim wpfEarth As New vASA.TheEarthWindow
wpfEarth.Show()

B. Dispatchers:
(calling function/sub):

Dim thread = New Thread(New ThreadStart(AddressOf Me.DisplayEarthOnThread))
thread.SetApartmentState(ApartmentState.STA)
thread.Start()
thread.Join()
[...]

Private Sub DisplayEarthOnThread()
    Try
        Dim wpfEarth As New vASA.TheEarthWindow
        wpfEarth.Show()
        AddHandler wpfEarth.Closed, Sub(s, e) wpfEarth.Dispatcher.InvokeShutdown()
        System.Windows.Threading.Dispatcher.Run()
    Catch ex As Exception
        [...]
    End Try
End Sub

C. A ton of random variations on:

Dispatcher.Invoke(Sub()
    Dim wpfEarth As New vASA.TheEarthWindow
    wpfEarth.Show()
    AddHandler wpfEarth.Closed, Sub(sender2, e2) wpfEarth.Dispatcher.InvokeShutdown()
    System.Windows.Threading.Dispatcher.Run()
        End Sub)

D. This is SUPPOSED to kill the child window when it closes, but doesn't (still unresponsive like the above ones):

Dim newWindowThread As New Thread(New ThreadStart(Sub()
                                                                  ' When the window closes, shut down the dispatcher
                                                                  ' Start the Dispatcher Processing
                                                                  Dim tempWindow As New TheEarthWindow()
                                                                  AddHandler tempWindow.Closed, Sub(s2, e2) Dispatcher.CurrentDispatcher.BeginInvokeShutdown(DispatcherPriority.Background)
                                                                  tempWindow.Show()
                                                                  System.Windows.Threading.Dispatcher.Run()
                                                              End Sub))
newWindowThread.SetApartmentState(ApartmentState.STA)
' Make the thread a background thread
newWindowThread.IsBackground = True
' Start the thread
newWindowThread.Start()

...
I could really use some insight... The parent is a stock WPF Window Project, and the Child is a HelixViewport3D window...

TIA!

pat
:)

I'm such an idiot...

I always tell people, and it may well be a part of Murphy's or Man Law, but if you are really stuck, just ask someone for help. The fact that you posted a request for help almost guarantees it is a stupid, silly oversight on your part.

Now, with the answer at hand, it WAS a stupid, silly thing, and one which had (relatively) little to do with Helix.

Suitably embarrassed, let's just leave it at "RTFM", shall we? :)

Thanks!

pat
:)

I am glad you solved it! I did not understand much of that code!
Maybe there should be a special forum for rubber duck problem solving? :-)

In the latest versions, there was a change to Items property of BillboardTextGroupVisual3D, from IList to List, so now i can't bind the ObservableCollections anymore.

I had a project that with the latest version stopped working because of this modification, so i had to take the source and recompile them with IList.
Maybe you should consider to return to IList as Items property for the next versions ?

/// <summary>
        /// Identifies the <see cref="Items"/> dependency property.
        /// </summary>
        public static readonly DependencyProperty ItemsProperty = DependencyProperty.Register(
            "Items",
            typeof(List<BillboardTextItem>),
            typeof(BillboardTextGroupVisual3D),
            new UIPropertyMetadata(null, VisualChanged));

 /// <summary>
        /// Gets or sets the items.
        /// </summary>
        /// <value>The items.</value>
        public List<BillboardTextItem> Items
        {
            get
            {
                return (List<BillboardTextItem>)this.GetValue(ItemsProperty);
            }

            set
            {
                this.SetValue(ItemsProperty, value);
            }
        }

thanks, that was a mistake. Fixed now. New version on Nuget will be available later today.

I checked the commit and there is also the UIPropertyMetadata callback that has to be changed; this is the old one that was working.

public static readonly DependencyProperty ItemsProperty = DependencyProperty.Register("Items", typeof(IList<BillboardTextItem>), typeof(BillboardTextGroupVisual3D), new UIPropertyMetadata(null, new PropertyChangedCallback(BillboardTextGroupVisual3D.VisualChanged)));

Thank you, your library is awesome !

you mean the new PropertyChangedCallback(? I think this is a redundant delegate constructor. Tested with NET 4.0 and 4.5.

Hey Guys,

I am using the BillboardTextGroupVisual3D, defined in xaml. I have the Items bound to an ObservableCollection<BillboardTextItem>, so when I add a BillboardTextItem to the Group all is well. When I attempt to detect the user clicking on one of the BillboardTextItems, I only see the BillboardTextGroupVisual3D, and I am unable to detect which actual item it is, so I can remove it from the group. I could come up with a algorithm to find the closest Item in the group based on the HitPoint? Is there something that can help already there somewhere...?? I,d rather not have to add BillboardTextVisuals for ever Item I want to display in the viewport...

Thanks again, Love the project
Chad

This is an interesting feature. It should be possible to add this to BillboardTextGroupVisual3D.
I added https://helixtoolkit.codeplex.com/workitem/10038

public static void LookAt(ProjectionCamera camera, Point3D target, Vector3D newLookDirection, double animationTime)

Viewport.Camera.Position = new Point3D(0,100,100);

    /// <summary>
    /// Binds this manipulator to a given Visual3D.
    /// </summary>
    /// <param name="source">Source Visual3D which receives the manipulator transforms.</param>
    public virtual void Bind(ModelVisual3D source)
    {
        BindingOperations.SetBinding(this, CombinedManipulator.TargetTransformProperty, new Binding("Transform") { Source = source });
        BindingOperations.SetBinding(this, CombinedManipulator.TransformProperty, new Binding("Transform") { Source = source });
    }

    /// <summary>
    /// Releases the binding of this manipulator.
    /// </summary>
    public virtual void UnBind()
    {
        BindingOperations.ClearBinding(this, CombinedManipulator.TargetTransformProperty);
        BindingOperations.ClearBinding(this, CombinedManipulator.TransformProperty);
    }

<Grid>
	<helix:HelixViewport3D>
        	<helix:DefaultLights/>
                <helix:CubeVisual3D SideLength="4" Fill="Blue"/>
                <helix:HelixViewport3D.Camera>
                	<PerspectiveCamera FieldOfView="{Binding Value, ElementName=FieldOfViewSlider}"/>
                </helix:HelixViewport3D.Camera>
        </helix:HelixViewport3D>
        <StackPanel HorizontalAlignment="Left" VerticalAlignment="Top" Margin="8">
                <Slider Name="FieldOfViewSlider" Value="45" Minimum="10" Maximum="160" Width="200"/>
        </StackPanel>
</Grid>

Hi,

Thank you for the great library.
I have successfully used the orthographic camera to display my scene, but with one problem:
when I zoom in my scene by moving the mouse wheel forward, I encounter the polygons clipping like it is shown in the picture:


I tried to reduce the camera near plane distance, but with no noticeable effect. Here is my camera definition:

            Camera = new OrthographicCamera
            {
                LookDirection = new Vector3D(-398.987, -42.626, -19.482),
                UpDirection = new Vector3D(-0.049, -0.001, 0.999),
                Position = new Point3D(398.987, 42.626, 19.482),
                Width = 235,
            };

Am I doing anything wrong?

My latest experiments showed that if I use "Zoom to mouse point" selection method, and there is a polygon under the mouse pointer, the issue seem to stop reproducing. I think this somehow may be related to use of GetNearestPoint method to calculate the camera target in this case, so the camera view matrix gets recalculated in more suitable way. Still have no exact thoughts how to fix the issue concisely.

Finally, I ended up using CameraHelper.LookAt to position the camera and OrthographicCamera.Width to zoom - manually, it doesn't produce the effects the CameraController does.

So , are there any changes to be submitted to the source code ?

@Mrme: no, I just used the library the other way to workaround my issue.

I can recreate this issue with the Camera example shipped with the toolkit. It happens with both zoom and rotation.

To reproduce, open the Camera demo, then switch to the Orthographic mode. Do some random zooming and rotating and you should be able to get it into a mode where the clipping is incorrect. In my trials, it seems that the incorrect clipping only affects the top and bottom regions, it does not appear to clip incorrectly on the left or right.

Sometimes the incorrect clipping is dynamic, e.g. the clipping line will move as you rotate the model whereas other times it is fixed.

Did you try changing the NearPlaneDistance?
The near plane distance should not be changed when zooming or rotating.
Currently the near plane distance is copied when the user change from perspective to orthographic, maybe this code should be removed.

The problem could also being related to the Position of the camera being too close to the model. The camera controller uses Position+LookDirection to define the target point that the camera rotates around. Maybe the problem is related to the length of LookDirection being changed when toggling between perspective and orthographic camera...
Set ShowCameraInfo = true on the HelixViewport3D to review the settings of the camera.

Hi objo,

That's essentially was the problem - I had universally specified my look directions as unit vectors, when in fact they need to be scaled to world units in order for the view to function correctly. I still think there is an issue when changing between orthographic and perspective projections (field of view explodes), but I cannot reliably recreate it.

In orthographic mode try to press "S" to move away from the target, or "W" to move closer.
Maybe zooming in orthographic mode should change the CameraPosition and LookDirection in the same way as for perspective camera.

@objo and @ezolotko
so what's the solution? Pressing "S" in my case solved the problem, but I just want to prevent the clipping happening.
From this:

Finally, I ended up using CameraHelper.LookAt to position the camera and OrthographicCamera.Width to zoom - manually, it doesn't produce the effects the CameraController does.

How can I leave the default mouse control and ovverride the Zoom function? Sorry, but it is not clear to me.

Giovanni

I finally solved changing the Helix source code in the file ZoomHandles.cs at line:

var newRelativePosition = relativePosition * (1 + delta);

changing it to:

var newRelativePosition = relativePosition * (1.1 + delta);

No more clipping and no need to use LookAt.

rinaldin wrote:

I finally solved changing the Helix source code in the file ZoomHandles.cs at line:

var newRelativePosition = relativePosition * (1 + delta);

changing it to:

var newRelativePosition = relativePosition * (1.1 + delta);

No more clipping and no need to use LookAt.

rinaldin,

I have the same issue when I use the latest Helix version. I checked the source codes and didn't find the ZoomHandles.cs file. Only ZoomHandler.cs found. Is it same file? Also, I didn't find the code

var newRelativePosition = relativePosition * (1 + delta); 

in the file ZoomHandler.cs.


Any comment and suggestion to resolve the problem?


Thanks in advance!

Yes, the file is ZoomHandler.cs, it was a typing mistake. Anyway, I noticed that in the later version of Helix Toolkit that code changes and it is written in a different way. I used the version helixtoolkit_f5a96293a071.

rinaldin wrote:

Yes, the file is ZoomHandler.cs, it was a typing mistake. Anyway, I noticed that in the later version of Helix Toolkit that code changes and it is written in a different way. I used the version helixtoolkit_f5a96293a071.

rinaldin,

Thanks for your reply. I found the latest revision changed from:

 var newRelativePosition = relativePosition * (1 + delta);
 var newRelativeTarget = relativeTarget * (1 + delta);

to

 var f = Math.Pow(2.5, delta);
 var newRelativePosition = relativePosition * f;
 var newRelativeTarget = relativeTarget * f;

The latest version still has the same issue. It is a great library. However, I am stuck in this step. Since I am new in WPF, I am wondering if you could send me correct HelixToolkit.Wpf.dll to me it will be greatly appreciated.
my email: wangzh2000@yahoo.com

I finally figured out the problem in other way as follows:

 public MainWindow()
        {
            InitializeComponent();
            resetZoom();
         }

Then write resetZoom()

private void resetZoom()
        {
            OrthographicCamera myOCamera = new OrthographicCamera(new Point3D(0, 0, 0), new Vector3D(100000, 100000, -100000), new Vector3D(0, 0, 1), 5000);
            ViewPort.Camera = myOCamera;
            
        }

Each time, when creating a model, using ZoomExtents() at the end of method, for instance:

double z1 = 0;
double h = 500;
        private void cylinder_Click(object sender, RoutedEventArgs e)
        {
            PipeVisual3D pipe = new PipeVisual3D();
            pipe.Point1 = new Point3D(0, 0, z1);
            pipe.Point2 = new Point3D(0, 0, z1+h);
            pipe.Material = Materials.LightGray;
            pipe.Diameter = 1200;
            pipe.InnerDiameter = 1180;
            z1 += h;
            SolidModels.Children.Add(pipe);
            ViewPort.ZoomExtents();
        }

I am a green bee in WPF and C#, any education and new simple way in the issue sharing will be greatly appreciated.

This WPF library package is great. Thanks objo for this work!!!


Cheers,

Hi,
I would like to create a curved surface to join two Cube faces together.
is this possible with helix3dToolKit?
I tried with AddExtrudedGeometry and AddLoftedGeometry but I didn't understand the right way to use them.

Did someone used those methods?

Thank You in advance for help

Regards