Unity教育类AR游戏：类似Pokemon Go的虚拟物体固定跨设备实现求助

Hey there! Let's tackle your AR game problem—building a Pokemon Go-style experience where a virtual object stays fixed in the real world, no image targets needed. I've got some practical tools and actionable steps that should work better for broader device support.

• Unity AR Foundation: This is your best bet for cross-platform coverage. It wraps ARCore (Android) and ARKit (iOS) into a unified API, so you get support for over 1 billion Android devices that run ARCore plus all iOS devices with ARKit support—way more than standalone ARCore/Vuforia's limited ground detection lists. It’s also actively maintained by Unity, so you’ll get ongoing updates.
• EasyAR: Another solid option with robust cross-platform plane detection. It’s beginner-friendly, doesn’t require image targets for ground placement, and works on most modern Android and iOS devices.

Let’s walk through the core setup to get your fixed virtual object up and running:

1. Set Up AR Foundation in Unity

   • Create a new 3D Unity project, then head to Window > Package Manager to install AR Foundation, ARCore XR Plugin (for Android), and ARKit XR Plugin (for iOS).
   • Add an AR Session component to a GameObject (this manages the AR session lifecycle) and an AR Session Origin component (handles camera positioning and real-world space mapping).

2. Enable Horizontal Plane Detection

   • Attach an AR Plane Manager component to your AR Session Origin GameObject. In the inspector, set the Plane Prefab to a default visualizer (or your own custom one) so you can see detected ground planes.
   • Set Detection Mode to Horizontal since you’re targeting ground surfaces.

3. Spawn a Fixed Virtual Object

   • Create a script (e.g., SpawnFixedObject.cs) and attach it to your AR Session Origin or a dedicated manager GameObject. Here’s a simplified example:

     using UnityEngine;
     using UnityEngine.XR.ARFoundation;
     
     public class SpawnFixedObject : MonoBehaviour
     {
         public ARPlaneManager planeManager;
         public GameObject virtualObjectPrefab;
         private bool hasSpawned = false;
     
         void Update()
         {
             // Wait until we detect at least one valid horizontal plane
             if (!hasSpawned && planeManager.trackables.count > 0)
             {
                 // Grab the first detected plane
                 ARPlane firstPlane = planeManager.trackables[0];
                 // Spawn the object at the plane's center
                 Instantiate(virtualObjectPrefab, firstPlane.center, Quaternion.identity);
                 // Disable plane detection to stop tracking new planes (keeps object fixed)
                 planeManager.enabled = false;
                 hasSpawned = true;
             }
         }
     }
     

   • Assign your AR Plane Manager and virtual object prefab in the inspector. When the app launches, it’ll detect the first ground plane, spawn your object there, and lock it in place by disabling further plane tracking.

4. Test and Refine

   • Build and test on target devices. For Android, ensure ARCore is installed (Unity will prompt users to install it if missing). For iOS, use an iPhone 6S or newer (ARKit’s minimum requirement).
   • If you want users to choose the object’s position instead of spawning it automatically, modify the script to listen for touch input: cast a ray from the tapped screen position, and spawn the object where the ray hits a detected plane.

If you prefer letting users pick the object’s location, use AR Foundation’s AR Raycast Manager:

• Add an AR Raycast Manager to your AR Session Origin.
• Update your script to cast a ray on touch input, check if it hits a real surface, and spawn the object at that hit point. This works even if the full plane isn’t detected yet.

• Device Compatibility: Use ARSession.state to show a warning if the device doesn’t support AR—AR Foundation handles compatibility checks automatically.
• Kudan Issues: Kudan has been less active in recent years, so it’s not surprising you hit roadblocks. AR Foundation is a more reliable, future-proof choice.
• Object Drift: If your virtual object shifts over time, ensure the environment has clear visual features (textures, edges) and good lighting—SLAM systems rely on these to track space accurately.

内容的提问来源于stack exchange，提问作者Ayhem