I was able to display a vector image with standard WPF like this.
<Image >
<Image.Source>
<DrawingImage>
<DrawingImage.Drawing>
<GeometryDrawing>
<GeometryDrawing.Pen>
<Pen Brush="#8F8E8F" Thickness="1" />
</GeometryDrawing.Pen>
<GeometryDrawing.Geometry>
<LineGeometry StartPoint="0,0" EndPoint="0,10"/>
</GeometryDrawing.Geometry>
</GeometryDrawing>
</DrawingImage.Drawing>
</DrawingImage>
</Image.Source>
</Image>
Unfortunately I was not able to do the same inside a Viewport3D element.
I created a VisualBrush from the Image and added it to the DiffuseMaterial of my 3D Model.
I also tried it via a DrawingBrush. Unfortunately the vector image gets renderd to a standard bitmap at some point of the pre-render processed. (that is what i think).
Is it even possible to display a vector image inside a Viewport3D?
Thank you for help in advance.