How to overlay images/videos on a Vuforia image target.
This article assumes you have successfully followed the steps outlined in How To Integrate Vuforia.
Use a Visual Marker Media Resource
Create a Script and navigate into that script. On the right hand side, drag and drop a Visual Marker Media resource into the center column. Beside Markers, click Add From Catalog. Now select 1 or more Vuforia image targets that you have already created. Next, choose an Audio or Video Media Item to assign to Media.
Now, when you run this script, the Visual Marker Media resource will assign your selected media to the selected image target. If you enter the camera-AR mode in your app you will see this media overlay the target.
Unassign Media to a Vuforia Target
Once this script runs, the media will stay assigned to the target indefinitely until the app shutdowns. To remove this assignment, use a Deactivate Resource resource and target the Visual Marker Media resource that is created earlier in the same script.