参考编号：Ar Fragment Blog
下面是一个AR片段在另一个片段中使用的例子。

import android.os.Bundle
import android.util.Log
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.annotation.Nullable
import com.google.ar.core.*

class MyFragment : Fragment() {

    private lateinit var arFragment: MyARFragment
    private var arShowing: Boolean = false

    override fun onCreateView(
        inflater: LayoutInflater, @Nullable container: ViewGroup?, @Nullable savedInstanceState: Bundle?
    ): View? {
        return inflater.inflate(R.layout.fragment_sample, container, false)
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        arFragment = childFragmentManager.findFragmentById(R.id.ar_fragment) as MyARFragment
        arFragment.arSceneView.scene
            .addOnUpdateListener {
                onUpdateFrame()
            }
     }

    private fun onUpdateFrame() {
        val frame = arFragment.arSceneView.arFrame ?: return
        // If there is no frame, just return.
        val updatedAugmentedImages =
            frame.getUpdatedTrackables(
                AugmentedImage::class.java
            )
        for (augmentedImage in updatedAugmentedImages) {
            when (augmentedImage.trackingState) {
                TrackingState.TRACKING -> {
                    if(!arShowing){
                        val anchor =  arFragment.arSceneView.session!!.createAnchor(augmentedImage.centerPose)
                        val node =
                            MyViewNode(context)
                        node.setImage(augmentedImage, anchor)
                        arFragment.arSceneView.scene.addChild(node)
                        arShowing = true
                    }
                }
                TrackingState.STOPPED -> {
                    arShowing = false
                }
            }
        }
    }
}