The answer is simple: you can't.
At least not the easy way. The
Viewport3D
control makes it possible to display 3D content in simple way, but there are many restrictions. For example it's not possible to draw lines (thus it's not possible to render a wireframe object, although there are workarounds) and basically all you can use are triangles...
You can use the
D3DImage class to host Direct3D content in a WPF application and have full control over the rendering process.