Thanks, but although that is one possibilty with small items it would not work with larger items and what we really would like is the target object removed/masked from view and then replaced by the 3D one.

I guess this is not possible?

Thanks

Perhaps you could consider using the Object Recognition new feature introduced with Vuforia 4.0, currently in beta version:

https://developer-beta.vuforia.com

With Object Reco, your coffe machine could be the Target itself (i.e. an Object Target), without having to use an Image Target.

so I could imagine the following scenario might potentially work (but you'll really need to try out and test to be sure):

- Vuforia detects the real Coffee Machine (as an "Object Target") and starts tracking your scene 

- you remove the real coffee machine from the scene

- Vuforia will raise a "target lost" event (as the target has moved away) => you now know that you can enable your "virtual 3D model" (virtual coffee machine)

- also, you will probably want to enable "Extended Tracking", so that Vuforia can still keep tracking your environment (after the target was removed)

One note:

Extended Tracking normally would require that your environment does not change; however, you could assume that if the coffee machine is the only element removed from your real world scene (and everything else remains as it was), the environment surroduning the Object Target might possibly be sufficient for Extended Tracking to keep tracking the real world consistently with the initial pose estimation.

See also:

https://developer-beta.vuforia.com/library/articles/Training/Vuforia-Object-Scanner-Users-Guide

https://developer-beta.vuforia.com/library/articles/Solution/How-To-Setup-an-Object-Scanning-Session

https://developer-beta.vuforia.com/library/articles/Solution/How-To-Edit-and-Upload-Object-Data-Files

https://developer-beta.vuforia.com/library/articles/Solution/How-To-Scan-an-Object-and-Create-an-Object-Data-File

https://developer.vuforia.com/resources/dev-guide/extended-tracking