2d 到 3d - 如何将绘图包裹在圆柱体上

Question

我有在3D空间中旋转的图纸（带有X和Y坐标的点的阵列）： http://www.motiondraw.com/mtdraw.com/mddraw.com/md/as_samples/tesmples/testesmples/testesting/testing/testing/_mindreadreadreadreder /main.html

现在，图纸看起来好像包裹在一个立方体上，角落里的90°程度。相反，它看起来好像被缠绕在圆柱体上。 在启动旋转之前，我称为函数（在ActionScript）“ benddrawing”，每个点都设置了一个初始z值：

for（var j = 0; j＆lt; numpoints; j ++）{
//绘图是集中的 - 中心的左点为＆lt; 0 var distfromcenter = math.abs（shape [i] .points [j] .x）;

var wid = 350;// this could be the radius of the cylinder

// NOTE: suboptimal, as the image gets a 90° corner in the center, at its highest point
// what it should look like: as if the image was wrapped around a cylinder, i.e. in a circular shape
// is that pythagoras? draw triangle, calc distance from base, add to this to c?
var z = wid - distFromCenter;

shape[i].points[j].z =  Math.abs( z);

}

我只是无法缠绕我的头;-) 任何指针都非常感谢！

安德烈亚斯·韦伯

Answer 1

试试这个：

shape[i].points[j].z  = 
    wid * Math.cos((shape[i].points[j].x / wid) * (0.5 * Math.PI));