Mat*_*Mat 5 mapping 3d projection texture-mapping
我正在寻找数学变换来将2D平面[0,1]x[0,1]上的点变换到单位球面上.
最常见的投影将纬度-经度映射通过解释u和v作为球面坐标的角度(映射u到[0,2PI]和v到[-PI/2, PI/2])
这会对球体的极点产生强烈的扭曲.人们可以把这种转变想象成将球体包裹成两端旋转纸张的糖果纸.这会在这两端造成扭曲.
The transformation I'm looking for can be rater thoght of putting the sphere into the middle of a paper and putting all sides around the sphere and twirl them together on a single spot - so you get a little paper-bag with your sphere in it. This yelds minimal distortion on the bottom of the "bag" and maximum distoriton on the top - and if seen from below, the distortion is equal in all directions.
Can someone tell me how to calculate this kind of mapping?
正确的答案取决于需要保留原始图像的哪些属性,因为每个不同的地图投影都会以不同的方式扭曲。有些保留区域,有些保留角度,有些保留距离。
假设案例与形状有关,那么我建议使用Dymaxion 贴图,但请注意,其平面表示并非完全矩形。
有关其他选项,请参阅科罗拉多大学的列表。