Unity安卓端AR场景加载崩溃求助（基于Google ARCore SDK）

Hey there, let's tackle this crash issue you're facing when loading that 100-model AR scene. Since it worked fine with 40 models, memory overload or inefficient resource handling is almost certainly the culprit. Let's break down the solutions, starting with figuring out the exact error first.

1. First, Capture the Crash Log (You Need This!) #

You mentioned you can't find errors in Unity—let's grab the actual crash logs from Android, which will tell us if it's an Out-of-Memory (OOM) error or something else:

• Use Android Studio Logcat: Connect your device to Android Studio, filter logs by Unity (verbose) and AndroidRuntime (error). Reproduce the crash, and you'll see the exact stack trace (look for java.lang.OutOfMemoryError or Unity-specific asset load errors).
• Use ADB Command: Open your terminal and run:

  adb logcat -s Unity:V AndroidRuntime:E
  

  This will spit out only Unity-related verbose logs and critical Android runtime errors, making it easy to spot the crash cause.

2. Optimize Model Resources to Reduce Memory Footprint #

100 models add up fast—let's slim them down:

• Batch Mesh Simplification:
  • For each model, go to its Model Import Settings → set Mesh Compression to High (this reduces mesh size without noticeable quality loss for most AR use cases).
  • Use tools like Blender to manually reduce polygon counts if needed (aim for <1k faces per model unless they're high-detail assets).
• Texture Compression:
  • In every texture's Import Settings, set Compression to ETC2 (RGB8) (Android's native efficient format) and enable Generate Mip Maps only if necessary. This cuts texture memory usage drastically.
• Static Batching:
  • Mark static models as Static (check the box in the Inspector), then go to Edit > Project Settings > Player > Android > Optimization and enable Static Batching. This combines static meshes into fewer draw calls and reduces memory overhead.

3. Load Models Dynamically (Don't Load the Whole Scene at Once) #

Instead of loading the entire AR scene with 100 models upfront, load them in batches or on demand:

• Split into AssetBundles: Package your models into smaller AssetBundles (e.g., 20 models per bundle). Load the AR scene first (without models), then load bundles one by one.
• Batch Loading Example:

  using UnityEngine;
  using UnityEngine.SceneManagement;
  using System.Collections;
  
  public class ARSceneLoader : MonoBehaviour
  {
      IEnumerator LoadARSceneAndModels()
      {
          // Load AR scene first (empty, no models)
          AsyncOperation sceneLoadOp = SceneManager.LoadSceneAsync("ARScene", LoadSceneMode.Additive);
          yield return sceneLoadOp;
  
          // Load models in batches of 20
          int batchSize = 20;
          for (int i = 0; i < 100; i += batchSize)
          {
              for (int j = i; j < Mathf.Min(i + batchSize, 100); j++)
              {
                  GameObject modelPrefab = Resources.Load<GameObject>($"Models/ARModel_{j}");
                  if (modelPrefab != null)
                  {
                      // Spawn at a default position or use AR hit test position
                      Instantiate(modelPrefab, new Vector3(0, 0, 2), Quaternion.identity);
                  }
              }
              // Give the system time to process, then clean up unused assets
              yield return new WaitForSeconds(0.1f);
              Resources.UnloadUnusedAssets();
              GC.Collect();
          }
      }
  
      public void StartARScene()
      {
          StartCoroutine(LoadARSceneAndModels());
      }
  }
  

• On-Demand Loading: If users don't need all 100 models at once, load them only when the user interacts with a UI button or AR marker.

4. Fix OBB (APK Expansion File) Loading Logic #

Since you're using split APKs, make sure the OBB is fully mounted before loading the AR scene:

• In Unity's Player Settings > Android > Publishing Settings, confirm Split Application Binary is checked—this ensures large assets are packed into the OBB.
• Add a check to verify the OBB is available before loading the scene. Unity automatically handles OBB mounting, but you can use UnityWebRequest to test if a model asset exists in the OBB before attempting to load it.

5. ARCore-Specific Optimizations #

• Disable unused ARCore features: Go to Edit > Project Settings > XR Plug-in Management > ARCore and set Depth Mode to Disabled if you're not using depth detection. This reduces CPU/GPU load.
• Use Instant Placement instead of full plane detection if your use case allows—it's lighter and faster to initialize.

内容的提问来源于stack exchange，提问作者Arigarasuthan