I've got the following task:
Attaching a ground layer (provided as an jpg-image) over an plant.
I thought that I've found an solution.
Live-Demo on CodePen: http://codepen.io/mizech/full/dXBoRq/
But it doesn't work as expected. If one zooms into or out the map the image doesn't scale bigger or smaller.
Moreover: The image is supposed to rotate with the map. That doesn't work neither.
Therefore my question:
What do I have to do to make it work the way it should (image scales when zoomed-in and -out, images follows when rotating) ?
Or should I choose a complete different approach?
Then any hints concerning code-examples are very appreciated.
Here my code so far:
var layer = new ol.layer.Tile({
source: new ol.source.OSM()
});
var control = new ol.control.FullScreen();
var center = ol.proj.transform([6.9690055, 49.2175355], 'EPSG:4326', 'EPSG:3857');
var overlay = new ol.Overlay({
position: center,
element: document.getElementById('plant')
});
var view = new ol.View({
center: center,
zoom: 17
});
var map = new ol.Map({
target: 'map',
layers: [layer],
controls: [control],
overlays: [overlay],
view: view
});
#plant {
width: 1300px;
height: 400px;
border: 1px solid black;
transform: rotate(16.5deg);
}
#plant img {
opacity: 0.6;
}
<div id="map" class="map">
<div id="plant"><img src="http://placehold.it/1300x400" alt="bild" /></div>
</div>
You can try to use another option to accomplish the preferred effect, there are two options I can think of:
1. Use ol.layer.Image(), code sample:
var extent = ol.proj.transformExtent([7.2, 49.3, 6.5, 49.1],
'EPSG:4326', 'EPSG:3857');
new ol.layer.Image({
opacity: 0.6,
source: new ol.source.ImageStatic({
url: 'http://placehold.it/1300x400',
imageExtent: extent
})
})
The extent is just a rough estimation yet.
2. Use a vector Layer to style an Icon using your image, already explained here:
https://gis.stackexchange.com/questions/130603/how-to-resize-a-feature-and-prevent-it-from-scaling-when-zooming-in-openlayers-3/
To rotate it along with the map use rotateWithView: true in your icon style, like this:
var iconStyle = new ol.style.Icon({
src: 'http://placehold.it/1300x400',
rotateWithView: true,
opacity: 0.6
});
Related
I followed the example from the openlayers book to add a static image on top of an osf layer. It works, but my image (256x256) is displayed as a rectangle. I tried around with the coordinates for the projection and checked out other posts here on, but I can't get my head around it why the image is not displayed as a square:
// Create map
var map = new ol.Map({
target: 'map', // The DOM element that will contains the map
renderer: 'canvas', // Force the renderer to be used
layers: [
// Add a new Tile layer getting tiles from OpenStreetMap source
new ol.layer.Tile({
source: new ol.source.OSM()
})
],
// Create a view centered on the specified location and zoom level
view: new ol.View({
center: ol.proj.transform([16.3725, 48.208889], 'EPSG:4326', 'EPSG:3857'),
zoom: 4
})
});
// Create an image layer
var imageLayer = new ol.layer.Image({
opacity: 0.75,
source: new ol.source.ImageStatic({
attributions: [
new ol.Attribution({
html: ''
})
],
url: 'https://placebear.com/256/256',
imageSize: [256, 256],
projection: map.getView().getProjection(),
imageExtent: ol.extent.applyTransform(
[0, 0, 16.3725, 48.208889], ol.proj.getTransform("EPSG:4326", "EPSG:3857"))
})
});
map.addLayer(imageLayer);
ol.source.ImageStatic was made to put a georeferenced image (e.g. a scan of a historic map) on a map. Is this what you have in mind? If you just want to display an image and anchor it to a location on the map, you'd better use ol.Overlay or an ol.layer.Vector with a feature with an ol.style.Icon.
That said, your image will only be displayed as square if the imageExtent set on your ol.source.ImageStatic results in a square on the projected map view.
I'm trying to center a tile layer in OpenLayers 3 but it seems to ignore the center attribute of the map. I know the height and width of the original big image if it helps.
here is my code (also available in jsbin):
<!DOCTYPE html>
<html>
<head>
<title>XYZ</title>
<link rel="stylesheet" href="http://openlayers.org/en/v3.13.0/css/ol.css" type="text/css">
<script src="http://openlayers.org/en/v3.13.0/build/ol.js"></script>
</head>
<body>
<div id="map" class="map" style="width: 100%; height: 500px; border: 1px solid #000;"></div>
<script>
var layer = new ol.layer.Tile({
source: new ol.source.XYZ({
url: 'http://thinker.cloudapp.net/test/{z}-{x}-{y}.png',
wrapX: false
})
});
var map = new ol.Map({
target: 'map',
layers: [layer],
view: new ol.View({
center: [0,0],
zoom: 2
})
});
</script>
</body>
</html>
How can I center the map, and if possible zoom to fit screen width or height?
Update:
I've updated the code and added a jsbin link too.
The original image size is 4864x3328 if it helps.
I think this has to do with projection and setting the grid size in pixels, but i couldn't find anything helpful.
My first answer isn't a good one. Go this way:
var pixelProj = new ol.proj.Projection({
code: 'pixel',
units: 'pixels',
extent: [0, 0, 4864, 3328]
});
var layer = new ol.layer.Tile({
source: new ol.source.XYZ({
projection: pixelProj,
wrapX: false,
url: 'http://thinker.cloudapp.net/test/{z}-{x}-{y}.png'
})
});
var map = new ol.Map({
target: 'map',
layers: [layer],
view: new ol.View({
zoom: 2,
center: [1364, 2400],
projection: pixelProj
})
});
http://jsfiddle.net/jonataswalker/6f233kLy/
To achieve this you'll need to wait until all tiles are loaded, then get the layer extent, finally fit the view to this extent.
var tile_loading = 0, tile_loaded = 0;
yourTileLayer.getSource().on('tileloadstart', function(evt){
++tile_loading;
});
yourTileLayer.getSource().on('tileloadend', function(evt){
++tile_loaded;
if(tile_loaded === tile_loading){
tile_loading = 0;
tile_loaded = 0;
// put some logic here to do just once
// all tiles are loaded - get the layer extent
var extent = yourTileLayer.getExtent();
map.getView().fit(extent, map.getSize());
}
});
I'm loading a GPX file into my OL3 code. Now i'd like to whole line that the GPX makes to be clickable with some extra information. Now I can't for the life of me find a way to click the line drawn for the route. What listener can I use?
I don't want to click on the whole map but just the line.
I've tried attaching click/singleclick to vector to no avail.
Any ideas on how to do so?
My code:
var raster = new ol.layer.Tile({
source: new ol.source.OSM()
});
var style = {
'LineString': new ol.style.Style({
stroke: new ol.style.Stroke({
color: '#000',
width: 3
})
}),
'MultiLineString': new ol.style.Style({
stroke: new ol.style.Stroke({
color: '#000',
width: 3
})
})
};
var vector = new ol.layer.Vector({
source: new ol.source.Vector({
url: 'kust.gpx',
format: new ol.format.GPX()
}),
style: function(feature) {
return style[feature.getGeometry().getType()];
}
});
var map = new ol.Map({
layers: [raster, vector],
target: document.getElementById('map'),
view: new ol.View({
center: [0, 0],
zoom: 2
})
});
Try adding the click on the map, and in the handler you check on wich feature you clicked. For example:
map.on('click', displayFeatureInfo);
function displayFeatureInfo( evt ){
//get pixel position of click event
var pixel = evt.pixel;
var features = [];
//loop through all features under this pixel coordinate
//and save them in array
map.forEachFeatureAtPixel(pixel, function(feature, layer) {
features.push(feature)
});
//the top most feature
var target = features[0];
//...rest of code
target.get('customProp')
}
EDIT
You can put some extra juice in your feature by inserting extra properies to the passed object. for example:
var myFeature = new ol.Feature({
geometry: ...,
labelPoint: ..,
name:...,
customProp1: ...,
anothercustomProp: ...
})
Like the title said I have a vector of points on a OpenLayers map that I need to turn into a heatmap. I already have this code below (which works just fine for me) but I need to add thousands of more points(in a different data file) and be able to visualize it with a density/heatmap. Its current state is a simple open street map with one layer of locations plotted on a world map! I would post an image but reputation rules...
<!DOCTYPE HTML>
<html>
<head>
<title>AIS Map Template</title>
<script src="http://www.openlayers.org/api/OpenLayers.js"></script>
<script>
function init() {
map = new OpenLayers.Map("mapdiv");
var mapnik = new OpenLayers.Layer.OSM();
map.addLayer(mapnik);
// ADD POINTS TO A LAYER
var pois = new OpenLayers.Layer.Vector("Ships",
{
projection: new OpenLayers.Projection("EPSG:4326"),
strategies: [new OpenLayers.Strategy.Fixed()],
protocol: new OpenLayers.Protocol.HTTP(
{
url: "./AISdecoded.txt",
format: new OpenLayers.Format.Text(
{
extractStyles: true,
extractAttributes: true
})
})
});
// ADD POINTS LAYER TO MAP
map.addLayer(pois);
var layer_switcher= new OpenLayers.Control.LayerSwitcher({});
map.addControl(layer_switcher);
var lonlat = new OpenLayers.LonLat(0,0).transform(
new OpenLayers.Projection("EPSG:4326"), // transform from WGS 1984
new OpenLayers.Projection("EPSG:900913") // to Spherical Mercator
);
var zoom = 1;
map.setCenter(lonlat, zoom);
}
</script>
<style>
#mapdiv { width:900px; height:600px; }
div.olControlAttribution { bottom:3px; }
</style>
</head>
<body onload="init();">
<p>AIS Map Data</p>
<div id="mapdiv"></div>
</body>
</html>
The testing data looks like this:
lat lon title description icon iconSize iconOffset
49.4756 0.13138 227006760 Navigation Status: 0 ship_sea_ocean.png 16,16 -8,-8
51.2377 4.41944 205448890 Navigation Status: 0 ship_sea_ocean.png 16,16 -8,-8
I have tried various methods to try and get a heatmap produced but unfortunaetly I'm a little lacking on the Javascript/HTML side of things. I have looked at the examples online including the earthquake example provided by OpenLayers but 99% of them deal with KML files and since I need this application to run offline on a localhost server I cannot do it that way.
I have attempted this without success, among other flailing:
var heatmapLayer = new ol.layer.Heatmap({
source: new OpenLayers.Layer.Vector("Ships",
{
projection: new OpenLayers.Projection("EPSG:4326"),
strategies: [new OpenLayers.Strategy.Fixed()],
protocol: new OpenLayers.Protocol.HTTP(
{
url: "./AISdecoded.txt",
format: new OpenLayers.Format.Text(
{
extractStyles: true,
extractAttributes: true
})
})
}),
opacity: 0.9
});
// Create a tile layer from OSM
var osmLayer = new ol.layer.Tile({
source: new ol.source.OSM()
});
// Create the map with the previous layers
var map = new ol.Map({
target: 'map', // The DOM element that will contains the map
renderer: 'canvas', // Force the renderer to be used
layers: [osmLayer, heatmapLayer],
// Create a view centered on the specified location and zoom level
view: new ol.View({
center: ol.proj.transform([2.1833, 41.3833], 'EPSG:4326', 'EPSG:3857'),
zoom: 4
})
});
I have a feeling this is much easier than I think it is but I have been trying to do this for about a week now and my patience is nearing its end. If you know how to do this specifically that's awesome! But if you don't, can you push me in the right direction? Any help is much appreciated, thanks!
EDIT
OK so I edited the code a bit to be fully OL3 and use a geoJSON approach. It now looks like this:
<!DOCTYPE HTML>
<html>
<head>
<title>AIS Map Template</title>
<script src="http://openlayers.org/en/v3.5.0/build/ol.js" type="text/javascript"></script>
<link rel='stylesheet' href='http://ol3js.org/en/master/css/ol.css'>
<script>
function init() {
var vector = new ol.layer.Heatmap({
source: new ol.source.GeoJSON({
url: './AISdecoded.geojson',
projection: 'EPSG:3857'
}),
opacity: .9
});
var osmLayer = new ol.layer.Tile({
source: new ol.source.OSM()
});
// Create the map with the previous layers
var map = new ol.Map({
target: 'map', // The DOM element that will contain the map
renderer: 'canvas', // Force the renderer to be used
layers: [osmLayer,vector],
// Create a view centered on the specified location and zoom level
view: new ol.View({
center: ol.proj.transform([2.1833, 41.3833], 'EPSG:4326', 'EPSG:3857'),
zoom: 4
})
});
}
</script>
<style>
#map { width:900px; height:600px; }
div.olControlAttribution { bottom:3px; }
</style>
</head>
<body onload="init();">
<p>AIS Map Data</p>
<div id="map"></div>
</body>
</html>
But it's still not working, only a map, no layer. This is the way I found how to do via examples like this one. Firebug is saying "TypeError: ol.source.GeoJSON is not a constructor" but I don't know how to do this any other way. pls halp, thanks!
Change this:
var vector = new ol.layer.Heatmap({
source: new ol.source.GeoJSON({
url: './AISdecoded.geojson',
projection: 'EPSG:3857'
}),
to:
var vector = new ol.layer.Heatmap({
source: new ol.source.Vector({
url: './AISdecoded.geojson',
projection: 'EPSG:3857',
format: new ol.format.GeoJSON()
}),
I don't want that the users see the blank field when dragging the map. I want restrict it. I didn't find any great resolution.
my map code:
var map = new ol.Map({
layers: [new ol.layer.Tile({
source: new ol.source.MapQuest({ layer: 'osm' }) }), vectorLayer],
target: document.getElementById('map'),
controls: ol.control.defaults().extend([
new ol.control.ScaleLine(),
new ol.control.ZoomSlider()
]),
view: new ol.View({
center: [-6217890.205764902, -1910870.6048274133],
zoom: 3,
maxZoom: 20
})
});
Problem:
There are a couple of things that you could do:
Set a background color or image on your map container like in the examples to make the white gaps look nicer.
.map {
...
background: url(map-background.jpg) repeat;
}
Set the minZoom property on the view to prevent the map from being zoomed out too far. But on large screens users might still see gaps.
view: new ol.View({
...
minZoom: 4
})
Or restrict the view extent to the tile boundaries (ol.proj.get('EPSG:3857').getExtent()). This is not yet included in OpenLayers, but you'll find a work-around in this question.