要追踪增强现实脸部网格顶点，您可以使用ARCore的人脸识别功能。以下是一个使用Java进行实现的示例代码：

import android.app.Activity;
import android.content.Context;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.opengl.Matrix;
import android.os.Bundle;

import com.google.ar.core.Anchor;
import com.google.ar.core.Camera;
import com.google.ar.core.Face;
import com.google.ar.core.Frame;
import com.google.ar.core.TrackingState;
import com.google.ar.core.exceptions.NotYetAvailableException;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;

public class MainActivity extends Activity {

    private GLSurfaceView mSurfaceView;

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

        mSurfaceView = findViewById(R.id.surface_view);
        mSurfaceView.setEGLContextClientVersion(2);
        mSurfaceView.setRenderer(new MyRenderer(this));
    }

    private class MyRenderer implements GLSurfaceView.Renderer {

        private Context mContext;
        private Face mFace;

        private float[] mViewMatrix = new float[16];
        private float[] mProjectionMatrix = new float[16];

        public MyRenderer(Context context) {
            mContext = context;
        }

        @Override
        public void onSurfaceCreated(GL10 gl10, EGLConfig eglConfig) {
            GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        }

        @Override
        public void onSurfaceChanged(GL10 gl10, int width, int height) {
            GLES20.glViewport(0, 0, width, height);

            float ratio = (float) width / height;
            Matrix.frustumM(mProjectionMatrix, 0, -ratio, ratio, -1, 1);
        }

        @Override
        public void onDrawFrame(GL10 gl10) {
            GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);

            Frame frame = ((MainActivity) mContext).mSurfaceView.getSession().update();
            Camera camera = frame.getCamera();
            mFace = frame.getUpdatedTrackables(Face.class).iterator().next();

            float[] projectionMatrix = new float[16];
            camera.getProjectionMatrix(projectionMatrix, 0, 0.1f, 100.0f);

            float[] viewMatrix = new float[16];
            camera.getViewMatrix(viewMatrix, 0);

            float[] modelMatrix = new float[16];
            mFace.getCenterPose().toMatrix(modelMatrix, 0);

            float[] mvpMatrix = new float[16];
            Matrix.multiplyMM(mvpMatrix, 0, projectionMatrix, 0, viewMatrix, 0);
            Matrix.multiplyMM(mvpMatrix, 0, mvpMatrix, 0, modelMatrix, 0);

            for (int i = 0; i < mFace.getMeshVertices().remaining() / 3; ++i) {
                float x = mFace.getMeshVertices().get(i * 3);
                float y = mFace.getMeshVertices().get(i * 3 + 1);
                float z = mFace.getMeshVertices().get(i * 3 + 2);

                float[] vertex = {x, y, z, 1.0f};
                float[] result = new float[4];
                Matrix.multiplyMV(result, 0, mvpMatrix, 0, vertex, 0);

                // 这里可以处理顶点坐标，例如：绘制、保存等
                // ...

            }
        }
    }
}

上述示例中，我们使用GLSurfaceView来渲染增强现实脸部网格顶点。在onDrawFrame方法中，我们通过Frame对象获取到最新的人脸对象mFace，然后遍历网格顶点坐标，并将其转换为屏幕坐标系进行处理。您可以根据需要对顶点坐标进行进一步处理，例如绘制、保存等。

请确保在AndroidManifest.xml文件中添加相应的权限和特性：

此外，还需要在build.gradle文件中添加相