actionscript-3 - 2d 到 3d - 如何将绘图包裹在圆柱体周围

Question

我有在 3d 空间中旋转的绘图（具有 x 和 y 坐标的点数组）： http ://www.motiondraw.com/md/as_samples/Testing/_mindreader/main.html

就像现在一样，这幅画看起来就像包裹在一个立方体上，角落里有一个令人讨厌的 90° 度。相反，它应该看起来好像被包裹在一个圆柱体上。在开始旋转之前，我调用一个函数（在 ActionScript 中）“bendDrawing”，它为每个点设置一个初始 z 值：

for (var j = 0; j < numPoints; j++ ) {
// 绘图居中 – 中心左侧的点 < 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);

}

我只是无法解决这个问题；-) 任何指针都非常感谢！

安德烈亚斯·韦伯

Answer 1

尝试这个：

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