OK, after trying all day, I've settled on a work-around solution. I started by tracking in all the characters at once and then set each button to set the scaling of each character. So, one character is sized correctly while the others are scaled down to nothing. Amazingly it actually works. No delay at all between character switching. Hope this work-around is helpful to others.

David

I'm sorry to say, I'm not programmer by any stretch of the imagination. I'm using Playmaker with Unity, the visual scriptor. Currently, all four characters are parented to the image target. The buttons are shooting set actions to show/hide each character. It's just that, the re-targeting of those characters are not happening automatically by the AR Camera. So, what can I do? Do I need to alter those scripts you mentioned? And how should that be done?

David

OnTrackingFound is only fired once each time the target is detected. So if you are tracking a target, and want to reassign the model while it's being tracked, you'll need to render the model and make it a child of the target using your button logic, within OnGUI(). You can use the same code as in OnTrackingFound to do this. 

Post the code you're using if that doesn't make sense.

Hi, Did some more poking around and have discovered that the augmented scene isn't hanging, but rather, the AR Camera needs to re-lock to the image target. So, when I launch the scene, one character shows up like it should, then when I touch a button on screen, the character hides and the another character is supposed to appear, but it doesn't unitl I move the iPhone off the image target and then bring it back to re-lock. Then the other character apprears and so on until all the characters are loaded for the first time and then I can finally rapid swich between characters.

So, is there a way to pre-load all the characters into the ARCamera?

David

Have you tried enabling / disabling the renderers for these models, rather than activating / deactivating the model's gameobject? The latency you're seeing may derive from the activation process. 

There's an example of how to obtain the renderers for a model in the DefaultTrackableEventHandler script.

e.g.

    private void OnTrackingFound()
    {
        Renderer[] rendererComponents = GetComponentsInChildren<Renderer>();
        Collider[] colliderComponents = GetComponentsInChildren<Collider>();

        // Enable rendering:
        foreach (Renderer component in rendererComponents)
        {
            component.enabled = true;
        }

        // Enable colliders:
        foreach (Collider component in colliderComponents)
        {
            component.enabled = true;
        }

        Debug.Log("Trackable " + mTrackableBehaviour.TrackableName + " found");
    }

If that's still too slow, you might try rendering them offscreen and then assigning the selected model as a child of the ImageTarget. So you're effectively hiding them until they should be presented on the target.