DongMini wrote at 2012-08-02 02:07:

Hi, First, great toolkit, thank you! 

holes in the box, what should I do?

objo wrote at 2012-08-09 00:48:

The best solution would be to create a MeshGeometry where the holes are modelled. It should not be difficult to do the tessellation if the holes have regular shape.

I would not recommend using textures with transparency to show 'holes' with wpf 3d...

DongMini wrote at 2012-08-09 02:46:

var point3d_Out = new[] {new Point3D(0, 0, 0), new Point3D(6, 0, 0), new Point3D(4, 3, 0), new Point3D(6, 7, 0), new Point3D(0, 7, 0)};

var point3d_Hole = new[] {new Point3D(1, 2, 0), new Point3D(3, 2, 0), new Point3D(2, 4, 0), new Point3D(3, 5, 0), new Point3D(1, 5, 0)};

The hole was created by using CuttingEarsTriangulator.Triangulate to you Is there any plan to support.

objo wrote at 2012-08-09 08:48:

I don't think the ear clipping method supports holes (http://en.wikipedia.org/wiki/Polygon_triangulation).

I have not planned to implement other triangulation methods, but maybe you can use code from other .net libraries?

DongMini wrote at 2012-08-10 02:23:

Other ". NET libraries" could not be found

hard to sell in the hole  wpf3d

I can not speak English well.
So, more brutal.
google translator, I can not thank you enough  

^^;; Hahaha


Thank you so much for letting me answer

objo wrote at 2012-08-24 09:37:

http://stackoverflow.com/questions/2222601/net-polygon-triangulation-library

http://stackoverflow.com/questions/406301/polygon-triangulation-with-holes

http://paulbourke.net/papers/triangulate/morten.html

http://paulbourke.net/papers/triangulate/

http://www.cs.cmu.edu/~quake/triangle.html (looks good, try P/Invoke!)

chinh_nguyen wrote at 2013-01-07 13:15:

Hi all, I am newbie in term of 3D programming with WPF, so please bear with my beginner question: how to create a circle in 3D with known center point and it is on a plane which perpendicular to a line?

chinh_nguyen wrote at 2013-01-09 10:15:

Found the answer when asking in stackoverflow, post here in case anyone interested:

http://stackoverflow.com/questions/14195196/how-to-create-a-circle-in-3d-with-known-center-point-radius-and-it-is-on-a-plan

lightxx wrote at 2012-11-29 07:28:

Hi guys!

I just stared using helix and WOW is this toolkit powerful. Probably a bit too powerful for programmers inexperienced in 3D modeling like me.

Are there any good primers for the Helix 3D Toolkit? A getting started guide, some sort of walk through or whatever? I tried to find something on google but failed.

thanks!

objo wrote at 2012-11-30 18:10:

I recommend Charles Petzold's book "3D programming for Windows".

In this library, the examples are probably the best ways to learn how to use it. All classes should also be XML commented, giving you some info through intellisense.

lightxx wrote at 2012-12-01 16:23:

thank you very much!

eonxxx wrote at 2014-03-09 15:19:

 <MeshGeometry3D Normals="0,1,0 0,1,0 0,0.99620003,-0.087200001 0,0.99620003,-0.087200001 1,0,0 1,0,0 1,0,0 1,0,0 0,-1,0 0,-1,0 0,-0.99620003,0.087200001 0,-0.99620003,0.087200001 -1,0,0
-1,0,0 -1,0,0 -1,0,0 0,0.98479998,-0.1736 0,0.98479998,-0.1736 1,0,0>

alexalthauser wrote at 2012-02-24 23:15:

Hi,

I'm working on a project where I need to show a series of vertices in 3d. I can't find any tutorials on how to hide/show lines and verts. I was wondering if Helix has anything that might help, or, if anyone knows of any examples that might be useful.

alexalthauser wrote at 2012-02-25 00:32:

Ah, never mind. I figured it out. =]

objo wrote at 2012-03-10 16:04:

Good. See the PointsAndLinesDemo and the latest bug fix.

RobPerkins wrote at 2012-09-04 23:07:

I'm still trying to sort out how Helix 3D arranges its axes by default. 

A HelixViewport3D can automatically display a coordinate system graphic which tracks with the camera by specifying this properties:

 <h:HelixViewport3D ShowCoordinateSystem="True" >

This displays three arrows, one each of red, green, and blue. 

The question is, which one corresponds to X, which to Y, and which to Z?

The reason for the question is related to the top view, which when clicked on by the view box displays the arrows as red increasing left, green increasing up, and blue increasing towards the camera. If this is an RHS, then the green corresponds to X. If it's an LHS, then it corresponds to Y. 

Thus, the operative other question becomes "how do I get the "top view" to rotate so that the X axis increases to the right of the screen, the Y axis increases to the top, and the Z axis points toward the camera?

objo wrote at 2012-09-04 23:17:

The red arrow has direction (1,0,0)
The green arrow has direction (0,1,0)
The blue arrow has direction (0,0,1) 

RobPerkins wrote at 2012-09-04 23:25:

objo wrote:

The red arrow has direction (1,0,0)
The green arrow has direction (0,1,0)
The blue arrow has direction (0,0,1) 

OK, that makes Helix's coordinate system a left handed system, with the "top U" view displaying X increasing left, Y increasing up, and Z increasing towards the camera, doesn't it? That is, a rotation proceeding from X=1 to Y=1 happens clockwise

Is there a convenient place to transform the coordinates so that you can get an RHS out of Helix, where the top view corresponds to my second question? 

RobPerkins wrote at 2012-09-05 00:49:

OK, I've done some more testing and it doesn't look like a problem with the coordinate system. 

I added this code to my viewport:

Private Sub VP_MouseMove(sender As Object, e As MouseEventArgs) Handles VP.MouseMove
  Dim q = Viewport3DHelper.FindHits(VP.Viewport, e.GetPosition(VP))
  If q.Count > 0 Then
    Coordinates.Text = q(0).Position.FormattedString
  End If
End Sub

 When in the "U" top view, tracking the mouse along my geometries shows X increasing to the right, and Y increasing up. 

However, while the axis display looks points correctly for Y and Z, it indicates X increasing to the left, which is false! The red arrow appears to have direction (-1,0,0), suggesting a transform in that viewport which is not accurate!

There is no problem with the coordinate system of the main viewport; it's RHS the way we discussed in another thread. It's the viewport onto the axis that I think needs attention. 

RobPerkins wrote at 2012-09-05 01:35:

OK, I've uploaded a small sample here:

http://db.tt/Y5vGU0hV

... to demonstrate what I mean. Position the running viewer in the "U" top view and run the mouse along the cube from left to right, observing the text below. The X coordinate increases to the right, but the red arrow points left! The Y coordinate increases up, with the green arrow pointing up, as it should, and a Front view shows that the blue arrow, indicating Z, points up with the Z coordinates increasing up.

That X coordinate arrow is inverted.  

RobPerkins wrote at 2012-09-05 01:44:

Found it.

In the project, the "Generic.xaml" file defined this XAML:

                            <Viewport3D x:Name="PART_CoordinateView" 
                                        Width="{TemplateBinding CoordinateSystemWidth}" Height="{TemplateBinding CoordinateSystemHeight}" Margin="0" 
                                        HorizontalAlignment="{TemplateBinding CoordinateSystemHorizontalPosition}" VerticalAlignment="{TemplateBinding CoordinateSystemVerticalPosition}" 
                                        ClipToBounds="False" Visibility="{TemplateBinding ShowCoordinateSystem, Converter={StaticResource BoolToVisibilityConverter}}">
                                <local:ArrowVisual3D Point2="-10 0 0" Fill="#964B4B" />
                                <local:ArrowVisual3D Point2="0 10 0" Fill="#4B964B" />
                                <local:ArrowVisual3D Point2="0 0 10" Fill="#4B4B96" />
                                <!--
                                <local:PieSliceVisual3D Normal="1,0,0" UpVector="0,0,1" InnerRadius="3" OuterRadius="6"  Fill="#80ff0000"/>
                                <local:PieSliceVisual3D Normal="0,1,0" UpVector="1,0,0" InnerRadius="3" OuterRadius="6"  Fill="#8000ff00"/>
                                <local:PieSliceVisual3D Normal="0,0,1" UpVector="0,1,0" InnerRadius="3" OuterRadius="6"  Fill="#800000ff"/>
-->
                            </Viewport3D>

The problem was in the vector defining Point2 for the X axis arrow:

                                <local:ArrowVisual3D Point2="-10 0 0" Fill="#964B4B" />

Changing the first value from -10 to 10 corrected the incorrect arrow direction. I don't know if this XAML is present in the current release bits of Helix as I found it in mine or if I twiddled it at one point in the past, since I'm using Helix source code in my project. Might be worth a check...

luca82 wrote at 2013-04-09 11:56:

objo wrote at 2013-04-15 12:16:

luca82 wrote at 2013-04-15 14:08:

cedrelo wrote at 2013-04-16 08:35:

luca82 wrote at 2013-04-16 12:53:

BogusException wrote at 2014-07-02 20:23:

objo wrote at 2014-07-11 21:52:

ejleigh wrote at 2012-06-12 03:28:

I have a terrain model with objects on top and I'm trying to find a good way to prevent the user from rotaing the scene such that he can look underneath the terrrain model. It seemed like the best way would be to derive a new class from CameraController and override the OnManipulationDelta method, but unfortunately you cannot set the camera contoller in the HelixViewPort3D. At the moment I'm setting the RotationSensitivity to a low value when the camera Up vector approaches level, but that only kindof works. It's not ideal. Is there a better way?

objo wrote at 2012-06-15 06:38:

The CameraController is created in the control template of the HelixViewport3D, so you have to override the control template. http://wpftutorial.net/templates.html

Or, use the Camera's Position and LookDirection coerce value callbacks, and enforce the Z values to to be positive and negative, respectively.

http://msdn.microsoft.com/en-us/library/ms754209.aspx
http://msdn.microsoft.com/en-us/library/system.windows.coercevaluecallback.aspx

I have not tried this, but I think it should work.

lightxx wrote at 2013-02-26 10:11:

objo wrote at 2013-03-13 07:12: