转换3D点上球体UV坐标 [英] Convert 3d point on sphere to UV coordinate

问题描述

我有一个球上的三维点，并希望从该转换，到球体上的纹理UV点。

可能有人指明了正确的方向，为好吗？我可以带一个纯数学的解决方案。

编辑：

我现在有这个，不返回正确的UV坐标。 p是在球面上的三维点 mesh.position是球体的位置

  VAR X =（p.x-mesh.position.x）/ 500;
变种Y =（p.y-mesh.position.y）/ 500;
VAR Z =（p.z-mesh.position.z）/ 500;

变种U = Math.atan2（X，Z）/（2 * Math.PI）+ 0.5;
变种V = Math.asin（Y）/ Math.PI±0.5;
 

解决方案

有关UV映射维基百科是正确的，但是你需要计算的UV坐标网格的每个顶点。然后，你需要变换UV坐标像素坐标：完美（3D）纹理映射在OpenGL 。下面是一个其他例子： http://www.cse.msu.edu/~cse872 /tutorial4.html 。您也可以尝试three.js。您还需要物理复制UV三角形。

I have a 3d point on a sphere and want to convert from that, to a UV point on the sphere's texture.

Could someone point in the right direction for the please? I can take a pure math solution.

Edit:

I currently have this, which does not return the correct UV coordinate. p is the 3d point on the sphere mesh.position is the position of the sphere

var x = (p.x-mesh.position.x)/500;
var y = (p.y-mesh.position.y)/500;
var z = (p.z-mesh.position.z)/500;                  

var u = Math.atan2(x, z) / (2 * Math.PI) + 0.5;
var v = Math.asin(y) / Math.PI + .5;

解决方案

The Wikipedia about uv-mapping is correct however you need to compute the uv coordinate for each vertex of the mesh. Then you need to transform the uv coordinate to pixel coordinate: Perfect (3D) texture mapping in opengl. Here is an other example: http://www.cse.msu.edu/~cse872/tutorial4.html. You can also try three.js. You also need to physically copy the uv triangle.

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