3D OSC is an openFrameworks application that sends OSC data from a 3DConnexion 3D mouse to any OSC enabled application.
In order to build this application in Visual Studio 2015, you need 3DConnexion's 3DxWareSDK. The SDK can be downloaded (once you have registered on their website for a developer account) at https://www.3dconnexion.com/service/software-developer/licence-agreement/sdk-download.html
You need to put the 3DxWareSDK folder in the OF/apps folder of your openFrameworks install, so that it is at the same level as myApps.