要更改或删除ARCore搜索地面时显示的图标，你可以使用ARCore的AnchorNode和ViewRenderable。以下是一个基本的示例代码，演示如何在搜索地面时更改或删除图标：

首先，在你的build.gradle文件中添加ARCore库的依赖项：

implementation 'com.google.ar:core:1.24.0'

然后，在你的activity_main.xml布局文件中添加一个ARSceneView，用于显示AR场景：

接下来，在MainActivity.java中实现以下代码：

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import androidx.appcompat.app.AppCompatActivity;

import com.google.ar.core.Anchor;
import com.google.ar.core.Config;
import com.google.ar.core.HitResult;
import com.google.ar.core.Plane;
import com.google.ar.core.Session;
import com.google.ar.sceneform.AnchorNode;
import com.google.ar.sceneform.rendering.ModelRenderable;
import com.google.ar.sceneform.rendering.Renderable;
import com.google.ar.sceneform.rendering.ViewRenderable;
import com.google.ar.sceneform.ux.ArFragment;
import com.google.ar.sceneform.ux.TransformableNode;

public class MainActivity extends AppCompatActivity {

    private ArFragment arFragment;
    private Session session;
    private boolean isIconVisible = true;
    private ImageView iconImageView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        arFragment = (ArFragment) getSupportFragmentManager().findFragmentById(R.id.arFragment);
        arFragment.setOnTapArPlaneListener((hitResult, plane, motionEvent) -> {
            if (plane.getType() != Plane.Type.HORIZONTAL_UPWARD_FACING) {
                return;
            }

            // 如果图标已创建，则删除它
            if (isIconVisible) {
                AnchorNode anchorNode = (AnchorNode) hitResult.createAnchor().getRenderable();
                arFragment.getArSceneView().getScene().removeChild(anchorNode);
                isIconVisible = false;
            }
            // 否则，创建并添加图标
            else {
                anchorIcon(hitResult);
                isIconVisible = true;
            }
        });
    }

    // 创建并添加图标
    private void anchorIcon(HitResult hitResult) {
        // 创建AnchorNode
        Anchor anchor = hitResult.createAnchor();
        AnchorNode anchorNode = new AnchorNode(anchor);
        arFragment.getArSceneView().getScene().addChild(anchorNode);

        // 创建ViewRenderable
        ViewRenderable.builder()
                .setView(this, R.layout.icon_layout)  // 设置自定义的图标布局
                .build()
                .thenAccept(renderable -> {
                    // 在AnchorNode上创建TransformableNode
                    TransformableNode transformableNode = new TransformableNode(arFragment.getTransformationSystem());
                    transformableNode.setParent(anchorNode);
                    transformableNode.setRenderable(renderable);
                    transformableNode.select();

                    // 获取图标ImageView
                    View view = renderable.getView();
                    ViewGroup viewGroup = (ViewGroup) view;
                    iconImageView = viewGroup.findViewById(R.id.iconImageView);
                    // 设置图标点击事件
                    iconImageView.setOnClickListener(v -> {
                        // 点击图标时删除图标
                        arFragment.getArSceneView().getScene().removeChild(anchorNode);
                        isIconVisible = false;
                    });
                });
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (session == null) {
            try {
                session = new Session(this);
                Config config = new Config(session);
                session.configure(config);
                arFragment.getArSceneView().setupSession(session);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        if (session != null) {
            try {
                session.resume();
                arFragment.getArSceneView().resume();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        if (session != null) {
            arFragment.getArSceneView().pause();
            session.pause();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (session != null) {
            arFragment.getArSceneView().destroy();
            session.close();
            session = null;
        }
    }
}

在上面的代码中，我们首先在onCreate