如何在 WPF 3D HelixToolkit 中显示图形边缘

Question

Good day. How to show figure edges in WPF? I implement figure in WPF, but i'm need to get figure wireframe. I tried to find any HelixToolkit manual, but it failed. Can you give me HelixToolkit manual?

My code:

<h:HelixViewport3D ClipToBounds="true">
    <h:DefaultLights/>
    <h:LinesVisual3D Thickness="10">
        <ModelVisual3D>
            <ModelVisual3D.Content>
                <GeometryModel3D>
                    <GeometryModel3D.Geometry>
                        <MeshGeometry3D
                        Positions=" 0,3,3 -3,3,3
                                    -3,0,3 3,0,3
                                    -3,0,-3 -3,3,0"
                        TriangleIndices="   0,1,2 2,3,0 5,0,3
                                            3,4,5 5,4,2 1,5,2
                                            0,5,1 3,2,4"/>
                    </GeometryModel3D.Geometry>
                    <GeometryModel3D.Material>
                        <MaterialGroup>
                            <DiffuseMaterial Brush="GreenYellow" />
                            <SpecularMaterial Brush="WhiteSmoke" SpecularPower="30"></SpecularMaterial>
                        </MaterialGroup>
                    </GeometryModel3D.Material>
                </GeometryModel3D>
            </ModelVisual3D.Content>
            <ModelVisual3D.Transform>
                <Transform3DGroup>
                    <RotateTransform3D>
                        <RotateTransform3D.Rotation>
                            <AxisAngleRotation3D x:Name="RotateHorizontal" Axis="0 1 0" />
                        </RotateTransform3D.Rotation>
                    </RotateTransform3D>
                    <RotateTransform3D>
                        <RotateTransform3D.Rotation>
                            <AxisAngleRotation3D x:Name="RotateVertical" Axis="1 0 0" />
                        </RotateTransform3D.Rotation>
                    </RotateTransform3D>
                </Transform3DGroup>
            </ModelVisual3D.Transform>
        </ModelVisual3D>
    </h:LinesVisual3D>
</h:HelixViewport3D>

Answer 1

There are no built in features to achieve this goal. You problem can be split up into to different ones:

1. How to get the sharp edge of your model,
2. How to draw lines with WPF (or Helix).

(1) To get those, you might need to build the topology of your mesh -> knowing the triangles connectivity. I recommend the HalfEdge data structure (there are others ling WingEdge if you're curious).

(2) WPF does not provide anything on that side, Helix has made an attempt but i don't recommend it... Your best shot would be to build small rectangle (using 2 triangles).

Here is an example of what it can do (I use OpenGL and an overlay in light blue, don't bother).

Without sharp edges :

With sharp edges in dark blue :