Vector tiles buffer is used to include data that is just outside of the tile. This data is used to prevent border effects when rendering the geometries. It is currently [hardcoded to 5 pixels](https://github.com/elastic/elasticsearch/blob/de2781f98696c1e6cfad2b5bf46fe752a5e3edbb/x-pack/plugin/vector-tile/src/main/java/org/elasticsearch/xpack/vectortile/feature/FeatureFactory.java#L63) but it should probably need to be user configurable by adding a new property on the vector tiles API which can change the value.




x-pack/plugin/vector-tile/src/main/java/org/elasticsearch/xpack/vectortile/rest/RestVectorTileAction.java
/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0; you may not use this file except in compliance with the Elastic License
 * 2.0.
 */
package org.elasticsearch.xpack.vectortile.rest;
import com.wdtinc.mapbox_vector_tile.VectorTile;
import com.wdtinc.mapbox_vector_tile.build.MvtLayerProps;
import org.elasticsearch.action.search.SearchRequestBuilder;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.SearchResponseSections;
import org.elasticsearch.client.internal.node.NodeClient;
import org.elasticsearch.common.document.DocumentField;
import org.elasticsearch.common.geo.GeoBoundingBox;
import org.elasticsearch.common.geo.GeoPoint;
import org.elasticsearch.common.geo.SimpleVectorTileFormatter;
import org.elasticsearch.common.io.Streams;
import org.elasticsearch.common.io.stream.BytesStream;
import org.elasticsearch.geometry.Rectangle;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.rest.BaseRestHandler;
import org.elasticsearch.rest.BytesRestResponse;
import org.elasticsearch.rest.RestRequest;
import org.elasticsearch.rest.RestResponse;