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(WebGL) Longitude / Latitude to 3D to UV
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// Check your coordinates space! | |
// Lat, Lon (SW) = -Lat, -Lon (NE) | |
// Lat, Lon (NW) = -Lat, Lon (NE) | |
// etc | |
var ray = new Ray() | |
/* | |
positionToUV | |
Converts a 3D world position to UV coordinates on a given sphere mesh | |
{pos} the 3D world position (on the surface of the mesh). | |
{mesh} the mesh to project onto | |
*/ | |
function positionToUV(pos, mesh) { | |
ray.set(pos, pos.clone().negate()) | |
let hits = ray.intersectObject(mesh) | |
if (hits.length) return hits[0].uv | |
} | |
/* | |
latLonToUV | |
Converts lat/lon coordinates into UV coordinates on the surface of a given sphere. | |
{lat} the latittude from the north | |
{long} the longitude, from the east | |
*/ | |
function latLonToUV(lat, lon, mesh) { | |
return positionToUV(latLonToPosition(lat, lon), mesh) | |
} | |
/* | |
latLonToPosition | |
Converts a lat, lon (NE) to a 3D world position. | |
{radius} the globe radius in world units | |
*/ | |
function latLonToPosition(lat, lng, radius = 1) { | |
let phi = (90 - lat) * Math.PI / 180 | |
let theta = (180 - lng) * Math.PI / 180 | |
let pos = new Vector3() | |
pos.x = radius * Math.sin(phi) * Math.cos(theta) | |
pos.y = radius * Math.cos(phi) | |
pos.z = radius * Math.sin(phi) * Math.sin(theta) | |
return pos | |
} | |
export const LatLon3D = { | |
positionToUV, | |
latLonToUV, | |
latLonToPosition | |
} |
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