openlayers3 加载百度地图：

 var projection = ol.proj.get("EPSG:3857");var resolutions = [];for(var i=0; i<19; i++){resolutions[i] = Math.pow(2, 18-i);}var tilegrid  = new ol.tilegrid.TileGrid({origin: [0,0],resolutions: resolutions});var baidu_source = new ol.source.TileImage({projection: projection,tileGrid: tilegrid,tileUrlFunction: function(tileCoord, pixelRatio, proj){if(!tileCoord){return "";}var z = tileCoord[0];var x = tileCoord[1];var y = tileCoord[2];if(x<0){x = "M"+(-x);}if(y<0){y = "M"+(-y);}return "http://online3.map.bdimg.com/onlinelabel/?qt=tile&x="+x+"&y="+y+"&z="+z+"&styles=pl&udt=20151021&scaler=1&p=1";}});var baidu_layer = new ol.layer.Tile({source: baidu_source});var map = new ol.Map({target: 'map',layers: [baidu_layer],view: new ol.View({center:  [12959773,4853101],zoom: 12})});

openlayers3 加载天地图：

路网
var tian_di_tu_road_layer = new ol.layer.Tile({title: "天地图路网",source: new ol.source.XYZ({url: "http://t4.tianditu.com/DataServer?T=vec_w&x={x}&y={y}&l={z}"})
});
map.addLayer(tian_di_tu_road_layer);
注记
var tian_di_tu_annotation = new ol.layer.Tile({title: "天地图文字标注",source: new ol.source.XYZ({url: 'http://t3.tianditu.com/DataServer?T=cva_w&x={x}&y={y}&l={z}'})
});
map.addLayer(tian_di_tu_annotation);
卫星影像
var tian_di_tu_satellite_layer = new ol.layer.Tile({title: "天地图卫星影像",source: new ol.source.XYZ({url: 'http://t3.tianditu.com/DataServer?T=img_w&x={x}&y={y}&l={z}'})
});
map.addLayer(tian_di_tu_satellite_layer);