ddklo wrote at 2012-01-30 15:55:

Hi.

I some circumstances the Geometry or TriangleIndices property on our models is null which causes the GetTotalNumberOfTriangles to throw an NullPointerException. Could you add some null checks or catch the exception?

Regards Dagfinn

objo wrote at 2012-01-30 20:45:

added null checks - see 74458.

behnam263 wrote at 2014-06-29 06:08:

objo wrote at 2014-07-02 13:13:

thiagoaguirre wrote at 2014-02-25 13:47:

Jac312 wrote at 2010-06-06 18:57:

objo wrote at 2010-06-07 07:44:

thanks for the feedback! good to hear that the zoomtofit function works for you!

stfx wrote at 2010-02-02 18:50:

Hey I just registered here to tell you how awesome that toolkit is. I use a modified version of it and it works perfectly. Do you have any progress on the code so far like object transformation (position, rotation, size) or maybe fit screen to object and fit to show all objects?

Please dont give up on it I really appreciate it.

Oh yeah you should consider to rename it to Helix Engine - sounds so much cooler :D

PS: I can send you the modifications if you are interested.

objo wrote at 2010-02-21 18:13:

Thanks for your feedback!! Sure, this project just started - I hope to get more work done on it soon. I have added you as a developer, you are welcome to submit improvements! There is a simple manipulator class for object transformation (translation only) in the toolkit now, but I am sure this needs more work. Do you have solutions to this? And the "fit screen to object" feature? That's a feature I would really like to have included!

Engine or toolkit - I like "toolkit" since this is mostly a collection of tools and helper classes - not replacing or encapsulating the wpf 3d engine. 

31337 wrote at 2012-11-27 12:28:

Hallo, is it possible to add the TextBillboardVisual3D as ModelUIElement3D?

31337 wrote at 2012-11-30 12:22:

Figured it out myself.

"ContainerUIElement3D" is the answer.

bennasi wrote at 2012-12-03 10:47:

Could you please elaborate on this a bit more? A code example would be nice. Thanks

vindex wrote at 2011-12-17 11:55:

Hi, 

First of all, great job, and thank you again. I'm a grateful user of Oxyplot, and here i find you again!

And now my question... have you any plans to give support to some CAD formats like .step, .sat,  or .iges?

objo wrote at 2011-12-19 09:24:

Sorry, no plans to implement readers for step, sat or iges. Only simple formats using triangular/quadrilateral meshes.

I might add import for a subset of the DXF format (polylines/curves and simple surfaces).

openNURBS is also interesting, would like to add a demo using the .net library:

http://download.rhino3d.com/openNURBS.NET/5.0/release/download/

Elementu wrote at 2012-02-22 15:53:

Hello.

I have several helix controls in my application. Some of them are froze to give the feeling of a 2D display than cannot be rotated.

The one that is not froze uses a perspective camera and the other 2D use Orthographic Camera.

The problem that I'm facing is that when I zoom into the 2D controls my objects flip upside down. this can be seen also on the view cube the view changes, however even if I bring the view(guiding myself after the view cube) as it was before the objects are still upside down.

However if I reset the camera the objects will be in the correct position.

Is there a way to prevent this behavior and stop it from happening?

Thank you in advance.

elementu wrote at 2012-02-23 11:07:

Hello,

What I discovered in my investigation is that in the CameraContoller.cs(HelixToolkit.Wpf.CameraController) in the OnTimeStep method at the point were the this.ZoomHandler.Zoom method is called, when the "this.zoomSpeed * time" parameter has a large value this bug will occur. In fact this bug occurred especially if I ran my application a slower machine. If I ran it on my main machine the bug only occurred if I added a thread.sleep of 500 or 1000 before calling the Zoom method.

So from the Zoom method the delta parameter is passed further in the ChangeCameraWidth method because my camera is an OrthographicCamera one.

Finally in the ChangeCameraWidth method to prevent the delta parameter from having a value that is too large  if the absolute value of the parameter is larger that 1 ( Math.Abs(delta) >= 1 ) then delta will take the value "delta = delta % 1" .

Having done this even if I add the delay or run the application on a slower machine the bug is not reproduced anymore.

I noticed that in the ChangeCameraPosition method that is called from the Zoom method in case my camera is a PerspectiveCamera not an OrthographicCamera there is a section of code with similar functionality to limit the value of the delta parameter.

if (delta < -0.5)
{
      delta = -0.5;
}

On a first look the behavior seems the same as before and everything looks all right with the change, except the bug that does not occur anymore.

What I want to ask you is what could be the implications of the change(the limitation of the delta value) I made, what is the case or were could it have a negative effect on the behavior or performance of the HelixToolkit ?

Thank you.

objo wrote at 2012-03-10 15:41:

thanks for debugging this! I added the clamping on the delta value as you suggested (change set c213bd42d8f7), and this seems to correct the problem. It limits the maximum zoom-out speed, but 50% zoom out per zoom event should be sufficient, I think.

stfx wrote at 2012-05-21 00:05:

Nice fix - btw this also occured on a perspective camera but yea fixed after that commit.

Another problem related to zooming is that if you zoom in too far (as far as you can) the camera will start to wobble at the end).

Fixed it by modifying the CameraHelfer.LookAt function like this:

        public static void LookAt(
            PerspectiveCamera camera, Point3D target, Vector3D newLookDirection, double animationTime)
        {
            Point3D newPosition = target - newLookDirection;

            // prevent zooming in until camera gets wobbly due to precision loss
            if (Math.Abs(newPosition.Z) > 0.01)
            {
                AnimateTo(camera, newPosition, newLookDirection, camera.UpDirection, animationTime);
            }
        }

EDIT: This fix is definately not correct

Tapir wrote at 2012-11-08 08:13:

I have a problem with adding new child to group. Regardless of which material i use, all figures are filled with color of the last added one. Any idea how to solve this problem?

        static private Model3DGroup DrawLayers(int noOfLayers)
        {
            Material materialFiber = new DiffuseMaterial(new SolidColorBrush(Colors.Lime));
            Material materialCopper = new DiffuseMaterial(new SolidColorBrush(Colors.Orange));
          
            HelixToolkit.Wpf.MeshBuilder builder = new HelixToolkit.Wpf.MeshBuilder();
            Model3DGroup group = new Model3DGroup();

            for (int i = 0; i < noOfLayers; i++)
            {
                if (i == 0)
                {
                    builder.AddBox(new Point3D(0, 0, 0), 15, 15, 1);
                }
                else
                {
                    builder.AddBox(new Point3D(0, 0, 2*i), 15, 15, 1);
                }

                MeshGeometry3D layer = builder.ToMesh();

                if (i % 2 == 0)
                {
                    GeometryModel3D model = new GeometryModel3D() { Geometry = layer, Material = materialFiber, BackMaterial = materialFiber };
                    group.Children.Add(model);
                }
                else
                {
                    GeometryModel3D model = new GeometryModel3D() { Geometry = layer, Material = materialCopper, BackMaterial = materialCopper };
                    group.Children.Add(model);
                }
            }
            return group;
        }

objo wrote at 2012-11-08 08:25:

move

var builder = new HelixToolkit.Wpf.MeshBuilder();

inside your loop?

otherwise you are appending more and more boxes to your geometry...

Tapir wrote at 2012-11-08 08:31:

Works perfectly. Thanks a lot!