为什么 Polyhedron 单独渲染效果很好，但不能与完整模型结合使用

Question

下面的代码试图制作一个简单的 3d 三角形作为较大模型的侧面支撑。

它本身运行良好，但是当我将它添加到更大的模型时，三角形的其中一条边没有渲染，我收到 "UI-WARNING: Object may not be a valid 2-manifold and may need repair!"[= 的警告24=]

更奇怪的是，当我单击 "save" 时，模型被重新绘制，模型显示完整，但缺少一侧。

我正在使用 OpenScad v.2019.05

我正在通过在它们周围制作一些小物体和 hull() 来解决这个问题。但是，我希望这段代码能够工作。

//For some odd reason, this module works well on its own. //It does does not render correctly when used as part of a larger model. //Then it will miss a side. //It shows correctly up when saving though. module supportTriangle(height=10, length=10, thickness=10){ trianglePoints = [ [ 0, 0, 0 ], [ thickness, 0, 0 ], [ 0, 0, height ], [ thickness, 0, height], [ 0, length, 0], [ thickness, length, 0]]; triangleFaces = [ [ 0, 1, 5, 4 ], [ 0, 1, 3, 2 ], [ 2, 3, 5, 4 ], [ 0, 4, 2 ], [ 1, 3, 5 ]]; polyhedron(trianglePoints, triangleFaces); }

我在与较大的模型结合渲染时收到 "UI-WARNING: Object may not be a valid 2-manifold and may need repair!" 警告

Answer 1

试试这个：

module supportTriangle(height=10, length=10, thickness=10){
    trianglePoints = [
    [ 0, 0, 0 ],
    [ thickness, 0, 0 ],
    [ 0, 0, height ],
    [ thickness, 0, height],
    [ 0, length, 0],
    [ thickness, length, 0]];

    triangleFaces = [
    [ 0, 1, 5, 4 ], 
    [ 2,3,1,0], // i reversed these to keep them clockwise 
    [ 4,5,3,2 ], // i reversed these to keep them clockwise 
    [ 0, 4, 2 ],
    [ 1, 3, 5 ]];

    polyhedron(trianglePoints, triangleFaces);

}
supportTriangle(10,10,10);
cube(5,center=true); // just an extra thing to make it error if order is wrong

见： https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Primitive_Solids#polyhedron 所有的面都必须有相同方向的点。当从外向内看每个面时，OpenSCAD 更喜欢顺时针。背面是从背面看，底部是从底部看等等。

为什么 Polyhedron 单独渲染效果很好，但不能与完整模型结合使用

Why does Polyhedron render well on its own but not in combination with complete model

rendering

openscad