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Questions tagged [map-projections]

A map-projection transforms the coordinates of the spherical earth to a flat map in cartesian (x,y) space.

A map-projection transforms the coordinates of the spherical earth, usually given in degrees (latitude, longitude), to a flat cartesian (x,y) space.
There is no perfect projection, it can be proved that each projection has a drawback, one have minor others major ones.

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ThreeJS - Project texture onto mesh surface

I'm looking to project a texture onto the surface of a mesh in ThreeJS. https://www.lanyardmarket.com/en/printed-tshirt This link achieves the result i'm looking for however i'm not sure how they achieved it. . I'll update this post as I research…
Zurdge
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Prevent a Latitude/Longitude based chunk system from mercator projection stretching

I'm working on an little mapbox based game and I'm currently working on an lat/lng based chunk system. The distance between each of them should be the same. As you can see in the example the width and height of each chunk are equal. The little grey…
genaray
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Calculating Mercator d3 scaling to match Leaflet zoom level

Given a Leaflet zoom level (0..22), how would I calculate D3 scaling value for geoMercator projection? At zoom=0, the whole world fits within a single tile (256x256). In tiles, the world size is 2^zoom x 2^zoom tiles.
Yuri Astrakhan
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Change projection in MSSQL for web mapping (Leaflet,Openlayer, OpenStreetMaps, GoogleAPI, ...) to WSG48 or any other format

I have some WKT/WKB data in the MSSQL server like this and would like to show them on the map with the help of leaflet, Openlayer, OpenStreetMaps, or GoogleAPI. My data look likes this: POLYGON ((1736946.0983 5923253.9175, 1736895.6852 5923333.9451,…
Mohsen Sichani
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Projecting a NumPy array of coordinates using pyproj

I have a NumPy array of latitude/longitude (WGS84) coordinates like this: coords = np.asarray([ [6.74219, -53.57835], [6.74952, -53.57241], [6.75652, -53.56289], [6.74756, -53.56598], [6.73462, -53.57518]]) I want to use the…
Uli Köhler
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How to center & scale map in d3js (use projection.center/translate/rotate?)

Given that I have topoJSON data of a given geographical feature and a specific projection. How should I center and scale the map to fit its parent object? It seems I can use either projection.rotate(), projection.translate() or projection.center()…
pac w
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Setting map limits in ggplot2 with Mercator projection

Very much related to this question I am trying to plot some world regions, now using a Mercator projection, but keep getting into trouble when adding x and y limits: ggplot(world, mapping = aes(x = long, y = lat, group = group)) + …
guyabel
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Proj4 reprojection using R

I am trying to reproject coordinates from WGS84 to MGA Zone 53, a UTM projection based on the GDA94 datum. I get infinity as my result, which is definitely incorrect. I am using R's proj4 package like so: > library(proj4) > df <- data.frame("x" =…
fmark
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Apply d3 geo projection to an image

I have an image of which I know the lower left and upper right coordinates of the mercator projection (lat/long). I added it to Google Maps as a google.maps.GroundOverlay, which gives me the correct result I've added some color markers on the…
Daniel F
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Why are Basemap south polar stereographic map projection coordinates not agreeing with those of data sets in the same projection?

Some satellite based earth observation products provide latitude/longitude information while others provide the X/Y coordinates within a given grid projection (and there are also some having both, see example). My approach in the second case is to…
Dusch
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Displaying projection-transformed text on a canvas-based D3 globe

I'm using D3's orthographic projection to build a rotating globe that gets drawn to a canvas. I'm adding shapes to the globe using d3.geo.*, particuarlly geo.circle. I would also like to display text on the globe (also via canvas), with the caveat…
Michelle Tilley
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How to draw orthographic projection from equirectangular projection

I have this image : I don’t know exactly what kind on projection it is, I guess equirectangular or mercator by the shape. It's the texture for an attitude indicator, b. I want to draw a orthographic projection, b or maybe a General Perspective…
luxcem
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How to tell KmlLayer about custom map projection?

I have a map with a custom projection (for maps.yandex.ru tiles) and default projection (Google and OSM tiles). When I add KmlLayer to map in the default projection it seems ok: But switching map to maps.yandex layer (in custom projection)... and…
1d10t
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Viewing Equirectangular Map

I'm writing an equirectangular map viewer, all the stuff I have found so far are about the projection, conversions and inverse ones, which is the easiest part. I don't want to use OpenGL or DirectX sphere texture solutions, I want to draw the image…
arashka
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How to make a map of 1/2 of Antarctica

I'm trying to make a map figure of half of Antarctica. I need to plot the western half (the Ross Sea half), from 120ºE to 60ºW. I've used reference code from a similar question to make the following figure: I've included the code that I'm using to…
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