I'm working on a project for an exhibition where an AR scene is supposed to be layered on top of a 3D printed object. Visitors will be given a device with the application pre-installed. Various objects should be seen around / on top of the exhibit, so the precision of tracking is quite important.
We're using Unity to render the scene, this is not something that can be changed as we're already well into development. However, we're somewhat flexible on the technology we use to recognize the 3D object to position the AR camera.
So far we've been using Vuforia. The 3D target feature didn't scan our object very well, so we're resorting to printing 2D markers and placing them on the table that the exhibit sits on. The tracking is precise enough, the downside is that the scene disappears whenever the marker is lost, e.g. when the user tries to get a closer look at something.
Now we've recently gotten our hands on a Lenovo Phab 2 pro and are trying to figure out if Tango can improve on this solution. If I understand correctly, the advantage of Tango is that we can use its internal sensors and motion tracking to estimate its trajectory, so even when the marker is lost it will continue to render the scene very accurately, and then do some drift correction once the marker is reacquired. Unfortunately, I can't find any tutorials on how to localize the marker in the first place.
Has anyone used Tango for 3D marker tracking before? I had a look at the Area Learning example included in the Unity plugin, by letting it scan our exhibit and table in a mostly featureless room. It does recognize the object in the correct orientation even when it is moved to a different location, however the scene it always off by a few centimeters, which is not precise enough for our purposes. There is also a 2D marker detection API for Tango, but it looks like it only works with QR codes or AR tags (like this one), not arbitrary images like Vuforia.
Is what we're trying to achieve possible with Tango? Thanks in advance for any suggestions.