I am creating a vector layer comprised of polygons from a KML file using Openlayers and I need to apply a "hash" pattern (diagonal striping) to the polygons. I know Openlayers doesn't natively support adding a background image to a polygon in a vector layer but I'm wondering if anyone has any ideas on how to accomplish this? The styling of a vector polygon appears to be limited to solid colors and opacity. If need be I'll extend OpenLayers to add this functionality in by manually drawing the hash lines within the polygon boundaries but I'm hoping someone has a simpler suggestion before I head down that road.
Using SLD this can now be done. Not sure if it's in version 2.11 or the trunk development but i saw the addition was committed about 6 months ago.
It uses an ExternalGraphic so you can set an image of whatever pattern or color you want.
Here's the Example
I have not try this yet, but I have similar problem.
The solution I will try is svg pattern.
OpenLayers has SVG.js which is used to draw polygons. I will modify that to support patterns.
Look Image -->
http://i2.aijaa.com/b/00653/9707550.jpg
In this example i have modified http://openlayers.org/dev/examples/behavior-fixed-http-gml.html example to demonstrate pattern usage. --> Could this be good solution?
Related
I would like to use this fork (updated to work with latest Leaflet version) of the Leaflet Zoomify plugin to display a custom map (huge texture ~30000x70000).
I need to work on the map with geo coordinates (to set markers) and wonder what's the best way to do it, since there is no way to set offset, scale or boundaries when initialising it through the plugin.
Initially I thought there should be a way in Leaflet to calibrate a TileLayer just like it's possible with ImageOverlay by setting the image bounds. But that doesn't seem to be the case.
Is this something the plugin should to take care of? In which case I would raise an issue in the repo.
I also saw the conversion methods
in Leaflet. I'm wondering if the best way to go is to convert the geo coordinates to pixels using those methods?
I'm also open to switch to another file format and plugin.
Any advice is highly appreciated.
Thanks a lot!
After all, I went on a totally different route without Zoomify, which I think makes more sense in my case.
I used QGIS to geo-reference my custom layer and export it as GeoTIFF following this tutorial. I uploaded it to Mapbox and baked it into a map style while mixing it with additional map features from Mapbox/OSM.
I've been searching but cannot seem to find a solution.
I have a GeoJSON file which is 170mb in size. It contains about 2500 polygons. Somehow I need to render it to a leaflet map. Evidently at that size I have no chance.
What will the easiest way to render this data? Am I able to create a complete transparent png which can simply be rendered over the world map. The huge size is due to the complexity and the number of polygons. At this point I don't need it to be interactive.
Thanks,
Brian
The easiest way is to create your own map tiles based on that data. There are a couple of ways of achieving this but my suggestion is that you use TileMill. It's free and very easy to use. So, basically you would:
Use TileMill and specify your GeoJSON file as the data-source
Configure how the map should be displayed (like the color of the polygons) with a special CSS-like language inside TileMill
Generate the tiles
Load a new TileLayer in your Leaflet map that references your files
I've actually written a tutorial some time ago that uses a .shp instead of a GeoJson, but should be similar enough:
http://build-failed.blogspot.pt/2012/03/custom-map-tiles-part-2-tilemill.html
I cannot argue with psousa's recommendation. For a straightforward presentation, TileMill is a great idea.
However, if you want to overlay your polygons onto another map, I reckon the only way is by using Mike Bostock's TopoJSON and D3.
The main TopoJSON page:
https://github.com/mbostock/topojson/wiki
An example at the scale you are talking about:
http://bl.ocks.org/mbostock/4206573
You'll have to shop around Mike's excellent examples on github to see how to combine leaflet with a D3 overlay.
I'm currently doing this successfully with hundreds of complex polygons. Haven't had the need to break into the thousands ... yet.
There is also geojson-vt, which apparently can to the tiling serverless on-the-fly - after a bit of loading time.
Just another humble suggestion.
I had successfully done loading 10000+ polygons and querying attributes by rolling out my own Geoserver and PostgreSQL DB + PostGIS instance and producing a WMS (not WFS), as you can see in the image.
But it is not straightforward to implement, especially if the geojson data is the original (and only) data
In that regard I would second psousa's answer to use TileMill.
Using the google maps v3 javascript API, it's possible to add 'GroundOverlays' as a picture. Have a look here:
http://jsfiddle.net/9YYJB/1/
However, I'm working on a project where I'm trying to add a texture to the whole world map. Obviously I can add a single, absolutely massive gif/png overlay but I'd rather add a tiling texture. I've been digging around in the API and can't find any way to do this.
Anyone have any ideas on how this could be done?
Thanks very much
Yes, what you want to use is an image map type. This allows you to add tiles on top of the regular Google Base Map. If you want to completely replace the Google tiles, you would need to implement a Custom Map Type. My favorite example of that is the Liberty City Map.
I have an extremely large picture of a map. Now I want to create a Map UI where the user can click to highlight regions and also have the functionality to zoom into the map.
Is the AREA tag the only way to go at this problem? My only problem is when I zoom in the map, the will be enlarged and so will the image that it contains, but how would I expand the AREA coordinates according to my zoom level? Is there a good approach for going at this problem?
AREA is the only way to represent polygons, unfortunately. You can read your coordinates from the AREA tag, scale them, and write them back. Rounding overlaps are a pain to deal with though.
One alternative is to use the BING maps API, which allows custom overlays. You need to create an overlay for each zoom level though.
Apply css to AREA MAP
I suggest SVG there, which would also solve your zoom problem. The only complication is that IE8 and below won't support it, and IE9 isn't being pushed through Windows Update to non-beta users yet.
Simple option: ImageMapster figures out most image area map things for you on the fly. IE6+, needs jQuery.
More complex, more powerful option: Raphael.js enables you to create fully controllable fully scalable SVG vector graphics in everything from IE6+ (doesn't need Flash). Bit of a steep learning curve, but it's very powerful.
I'm trying to implement a LineString extrusion depending on timestamp. As mentioned on github it is supposed to be implemented, but it isn't. It is supposed to look something like the screenshot below.
So far I could find out that it is possible to use extrusion for polygons but then i would have to somehow create polygons from my LineStrings and circles. Is there another way to implement this? My plan is to show human movement in association with there timestamps (smallest z-axis heigth/altitude would represent the oldest timestamp).
Maybe there is another framework where this is possible but so far i m very pleased with MapboxGl JS. Thanks for anyhelp.
You can only extrude polygon. You could use turf buffer to create polygon features from your linestring segments.
UPDATE:
I ended up using fill-extrusion. I created Polygons between my geo points and extruded the or as mention it works perfectly with turf as well.