在 openSCAD 中用多面体创建 "cup"

Question

我正在尝试用八角棱柱（使用 polyhedron 函数）创建一个 "cup" 形状（空心，一端开口）。当我渲染我的代码时，OpenSCAD 不会渲染底面和内面。我做错了什么？

谢谢！

我的代码：

difference() {
    polyhedron(points = [ [21.5,51.9,0],[51.9,21.5,0],
    [-21.5,51.9,0],[-51.9,21.5,0],
    [-21.5,-51.9,0],[-51.9,-21.5,0],
    [21.5,-51.9,0],[51.9,-21.5,0],
    [21.5,51.9,100],[51.9,21.5,100],
    [-21.5,51.9,100],[-51.9,21.5,100],
    [-21.5,-51.9,100],[-51.9,-21.5,100],
    [21.5,-51.9,100],[51.9,-21.5,100] ], faces = [
    [0,1,9,8],[2,0,8,10],[3,2,10,11],[5,3,11,13],
    [4,5,13,12],[6,4,12,14],[7,6,14,15],[1,7,15,9],
    [0,1,7,6,4,5,3,2],[8,9,15,14,12,13,11,10] ]);

    polyhedron(points = [ [19,49.4,5],[49.4,19,5],
    [-19,49.4,5],[-49.4,19,5],
    [-19,-49.4,5],[-49.4,-19,5],
    [19,-49.4,5],[49.4,-19,5],
    [19,49.4,100],[49.4,19,100],
    [-19,49.4,100],[-49.4,19,100],
    [-19,-49.4,100],[-49.4,-19,100],
    [19,-49.4,100],[49.4,-19,100] ], faces = [
    [0,1,9,8],[2,0,8,10],[3,2,10,11],[5,3,11,13],
    [4,5,13,12],[6,4,12,14],[7,6,14,15],[1,7,15,9],
    [0,1,7,6,4,5,3,2],[8,9,15,14,12,13,11,10] ]);
}

我的渲染问题的图像：

Answer 1

如果您使用 polyhedron()，您应该始终按照此处所述检查面部的方向： documentation openscad

你会看到，在这两种情况下 bottom-face 的方向都是错误的，这里你的内部 polyhedron():

将 bottom-face 的 [0,1,7,6,4,5,3,2] 替换为 [2,3,5,4,6,7,1,0]，您就得到了杯子：

在 openSCAD 中用多面体创建 "cup"

Creating a "cup" with polyhedra in openSCAD

rendering

openscad

polyhedra