使用easyAR Unity开发AR应用：AR对象无法二次显示的问题求助

Hey there, let’s troubleshoot why your AR object won’t show up the second time in your easyAR Unity app. I’ve dealt with similar quirks before, so here are the most likely fixes to try out:

A super common issue is that the AR object or tracking target doesn’t get reset correctly after the first display.

• If you’re disabling the object with SetActive(false) when it’s not needed, make sure you explicitly call gameObject.SetActive(true) when you want it to reappear. It’s easy to forget this step if your logic only handles the first activation.
• For easyAR’s ImageTargetController, check if tracking isn’t resetting after losing the target. Try calling ImageTargetController.ResetTracking() right before you expect the object to show up again—this forces the system to re-scan for the target fresh.

Sometimes the AR Session gets paused or stopped accidentally after the first use, and doesn’t restart for the second display.

• Double-check your code for any calls to ARSession.Pause() or ARSession.Stop() that aren’t paired with a ARSession.Resume() or ARSession.Run() when you need to show the object again.
• Verify that the ARSession component has RunOnStart enabled, or manually trigger ARSession.Run() in your logic when initiating the second display.

If you’re spawning the AR object via instantiation or using an object pool, mismanaged state here often causes second-time failures.

• Object Pooling: Make sure pooled objects are fully reset—position, rotation, and active state—before reusing them. If you leave a pooled object disabled or stuck off-screen, it won’t show up even if assigned to a target.
• Fresh Instantiation: If you’re creating a new object each time, confirm that your instantiation code actually runs the second time. For example, if you only bind the instantiation to the OnTargetFound event once, but the event isn’t re-triggered, nothing will spawn. Add debug logs here to confirm the code executes.

easyAR’s event callbacks are your best friend here—they’ll tell you if the problem is with tracking or your object display logic.

• Bind methods to the ImageTargetController’s OnTargetFound and OnTargetLost events, like this:

  public void HandleTargetFound()
  {
      Debug.Log("Target detected! Attempting to show AR object.");
      // Insert your object display logic here
  }
  
  public void HandleTargetLost()
  {
      Debug.Log("Target lost—hiding AR object.");
      // Insert your object hiding logic here
  }
  

• Check the Unity Console: If HandleTargetFound doesn’t fire the second time, your tracking is the problem. If it does fire, the issue is in how you’re showing the object.

Occasionally, layer misconfigurations make the object invisible even if it’s active.

• Ensure your AR object is on a layer that’s included in the ARCamera’s Culling Mask. The Default layer works for most cases, but double-check if you’ve customized layers.
• Confirm the ARCamera is set to render the correct layers—if your object’s layer is excluded, it’ll never show up, no matter how many times you activate it.

Old SDK versions can have hidden bugs with tracking state persistence.

• Update easyAR to the latest stable release—developers often fix these exact second-display issues in newer versions.
• Make sure your Unity version is compatible with the easyAR version you’re using (e.g., easyAR 4.x requires Unity 2019.4 or later). Mismatched versions can cause unexpected behavior.

内容的提问来源于stack exchange，提问作者Kuro neko