[abenedik]

For cases when you need to display the text that faces the camera I would recommend that you create an overlay canvas, put the text in TextBlock element and calculate the TextBlock position with using Point3DTo2D method on the camera (to create a 2D position of a 3D point).

You will also need to update the position on each camera change and on Viewport3D size changed (so subscribe to those two events).

The overlay canvas control need to be created after the Viewport3D and should occupy the same space as Viewport3D - for example:

<Grid>
<Viewport3D ... />
<Canvas Name="OverlayCanvas">
<TextBlock Name="OverlayTextBlock" Text="..." />
</Canvas>
</Grid>