My objective here is to allow users to specify territories or regions given a background world-map overlay, which is an SVG generated from GeoJSON data using D3. I have done the part where the territories' points are pinpointed by the user, and an SVG is generated. This works well.
Now I would like to save the territory's coordinates, using the background map's projection, scale and translation. I saw a lot of documentation about translating GeoJSON data to SVG s, but nothing about the other way. Is it even possible ?
Thanks Ben Lyall, eventually I used the native SVG functions getTotalLength() and getPointAtLength() to convert my path to an array of top/left positions (in pixels), then d3's projection.invert() to translate them into coordinates.
Related
For my web app, I am creating SVG elements in Illustrator and then using them in a library of elements that users can add to the fabric canvas.
Some elements are simple but some complex with multiple compound paths etc.
I have came across an unusual issue where if I create a path with a gradient fill, and then copy that path, save the SVG and add it onto the canvas, only the first path would have the gradient and the rest would be flat colors.
Here is a screenshot of what I mean...
After experimenting and trying different things, I finally discovered that this is happening because the paths have the exact same gradient properties.
So if the gradient slider (color stops, opacity, location etc.) of two or more paths have the exact same properties in Illustrator, then the issue occurs.
So the workaround is to alter something like the location (for example) to be 99.9% instead of 100% on the copied path, then the issue goes away. However, this will quickly become a tedious and annoying way to fix this. Basically, each path with a gradient, needs to have a unique gradient set up and cannot be identical to another paths gradient properties.
Here are more screenshots to better explain...
After making this change...
The first and second path's gradient's location are different.
The first, third, fourth and fifth paths have exact same gradient.
This is what it looks like when I add it to the canvas now...
Here is the code I am using to add the SVG to the canvas...
fabric.loadSVGFromURL(image, function(objects, options) {
var oImg = fabric.util.groupSVGElements(objects, options);
oImg.perPixelTargetFind = true;
oImg.targetFindTolerance = 4;
canvas.add(oImg);
canvas.renderAll();
});
Can anyone tell me why this is happening and if there is a way to fix this with code rather than Illustrator? I have hundreds of elements to create that will have many paths with the same gradients. I know it will be a real pain to have to worry about paths not having the exact same gradient.
http://jsfiddle.net/oc70xjsq/
Link to the SVG
I'm trying to generate a 3d map of the boroughs of London using Three js. I've reverse engineered this example: http://threejs.org/examples/webgl_geometry_extrude_shapes2.html
using this svg file: https://upload.wikimedia.org/wikipedia/commons/2/29/London-boroughs.svg
So, I'm passing svg path strings such as:
M130.833,250.833L135.5,262.5l14,42.667l-6.333,4l-4.667,3.667l1,3.666l-14.333,3 c0,0,0.333,3.334,4.667,5.667s16,2.667,17,3.667s0.667,6.333,0.667,6.333l-5.667,6.333l-0.667,6.667l-1.667,2l-3.333,1.333l-4.667,6 l-1.333,10l-2.667,8l-4-0.333c0,0,0.667,6.001-0.333,9.667s-2,9.666-5,11.333S112.5,396,112.5,396"
into the transformSVGPath function, and it kind of works except the vertices seem to be interpolated badly.
I get the console error "three.js:34023 THREE.ShapeUtils: Unable to triangulate polygon! in triangulate()" and it looks like this:
On examination of the SVG, it is a collection of lines over a primary closed shape. The primary shape is the first element in the SVG file and encompasses all of London. The rest of the paths are simply lineTo and bezier curves which define the borders. This is done so that the svg file size will be efficient and that shared edges of boroughs are not doubled - a classic 2d mapping issue. 3d is a different problem space - extrude path in Three.js requires discrete outline shapes to form a complete closed shape. This SVG file is unusable for 3d or polygons. You're better off finding each borough as a single SVG/polygon and importing them each individually if you can find them.
I believe you will find this file more usable as each borough is a discrete shape, but it will still need tayloring to remove the strokes: https://commons.wikimedia.org/wiki/File:London_boroughs.svg
I'm trying to rotate and scale shapes within an SVG around their center point. I've looked into several libraries, including Jquery, Greensock, D3, RaphaelJS, but I haven't been able to find any that provide a straightforward way to accomplish this. Each animates the shape from the origin point (which I understand is the default). I want to be able to spin a shape around its center point or scale it up or down from the center point.
Here are a couple examples using Greensock and D3 that illustrate the default behavior: http://jsbin.com/AHEXiPa/1/edit?html,js,output
Each of these examples bounce in and out from the top left as opposed to remaining stationary and expanding from the center of the triangle out in all directions.
Can one of the libraries I mentioned accomplish this, or is there another library or method I should consider?
Ideally, I need to be able to apply the animation/transform to an existing object in the DOM. D3 is good at this for instance, but Raphael seems to require converting an SVG to Raphael first prior to injecting it into the DOM.
Really its a case of pick the library that suits your needs, and then you will figure a way. As BigBadaboom says, if you do a search, there are lots of solutions.
To try and combine your questions, as sometimes the tricky bit is using an existing DOM object, I've included an example in Snap.svg. You can often do something similar in most libraries.
jsfiddle here Fiddle using your existing html.
s = Snap("#mySVGContainer1"); // create a canvas from existing svg
var triangle1 = s.select("#myShape1").transform("r90"); //select&transform existing object
p = Snap("#mySVGContainer2");
var triangle2 = p.select("#myShape2");
var bbox = triangle2.getBBox(); //bounding box, centre cx/cy
//rotate and scale with transform string (raphael/snap format)
triangle2.animate({ transform: "r180," + bbox.cx + ',' + bbox.cy + "s3,3," + bbox.cx + "," + bbox.cy }, 2000);
For rotations, as #Ian points out, you can specify the center of rotation. For other transformations, changes are defined relative to the path's (0,0) point.
The easiest way to get transformations to work relative to the path's center is to either:
Define the path so that it is centered around the (0,0) point; or
Wrap the path in a <g> element, and then translate it so it is centered on the (0,0) point of the <g> element's coordinate system.
Then, you can apply rotations, scales and transforms (on the <g> element, if using) and they will all be nicely centred.
The trickiest part is figuring out the "center" of an arbitrary shape. #Ian's approach of using the center of the bounding box will usually give decent results. If your shape is a polygon there are d3 functions you could use.
Example showing a shape moving with the mouse, rotating and changing scale, all centered around the center of the bounding box:
http://fiddle.jshell.net/LgfE3/
Edit: simplier jsfiddle
I've been looking for a long time, and will settle for the following.
1. Design your svg shape at coordinate x:0,y:0.
2. Identify by hand the center of rotation, by example, center = [ x:50,y:100].
3. Build a spinIt() function such :
function spinIt() {
needle.transition()
.duration(2000)
.attrTween("transform", tween);
function tween() {
return d3.interpolateString("rotate(-180, 50, 100)", "rotate(90, 50, 100)");
}
}
4. Use it on a triger:
svg.on("click", spinIt);
http://jsfiddle.net/SHF2M/79/
I'm working with nokia HERE maps and I want to add an additional layer of visualization graphics on top of a map. Since the possibilities to interact, manipulate and customize the graphics created by the HERE api are limited, I would like to work with d3.js/SVG for my visualizations.
My straight forward and obvious solution would have been to just add an absolute positioned SVG element on top of the map and giving it the same dimensions. But of course that takes every possibility to interact with the map. Is there any solution to add an overlay to the map which allows me to put SVG on it while maintaining the full interactivity (panning, zooming, clicking) of the map? Also it should be possible to interact with the SVG.
I know that there is a possibility to add a custom overlay of tiles provided by a tile server to HERE maps but that's not really what I'm looking for. I'm looking for something like the solution google has to offer to this problem. A set of custom layers which are always in sync with the corresponding map and have their own initialize, draw and remove methods. Is there something similar for HERE maps?
I think you are after the nokia.maps.map.provider.CanvasProvider class. This class provides a ground overlay bound to a specific area which offers a draw() method. The attach() method is the equivalent of your intialize I think, and you can refresh the overlay using update().
Depending upon your use case, I've also found the following techniques useful regarding SVG, Images and HERE Maps:
For an SVG marker which is anchored to a point and doesn't resize
use: SVG Markers
Alternatively override the Marker class and write using the low
level graphics commands to add flexibility to the rendering of a
marker anchored to a point. Like this: Defaced Marker
To add an image bound to a specific area use the ImageProvider class
To add a series of tiled images from a TMS (Tile Map Service) use the ImgTileProvider class
Alternatively if the [zoom][col][row] is useful to you and you
want to write SVG based stuff yourself try something like this example - which combines
SVG with 256x256 pixel markers.
Note that the HERE Maps API for JavaScript only supports SVG Tiny.
A class like the old nokia.maps.map.provider.CanvasProvider isn't even available on the new v3 API from Here.
Your best bet is on Leaflet using custom providers loading Here map tiles. Then you just load this Custom Overlay class and you're all set to draw D3, WebGL, whatever you need. Leaflet only loads the tiles from the providers and exposes some simple APIs. You will not have to deal with any of the providers' APIs.
Just don't forget to add your app_id and app_code to the provider class.
Is there any way to create an SVG transform that would transform a square into an isosceles trapezoid to give the illusion of perspective?
I have a project (visible here) where I have one element group in the svg (the breadboard) that I would like to skew so that the bottom looks like it's a closer to the user.
I can transform the top-level SVG DOM element with a CSS transform (in supporting browsers) using something like "-webkit-transform: perspective(1000px) rotateX(40deg);", but this doesn't work in the nested group element.
Any suggestions appreciated, thanks!