我是一名新手程序员，使用Javascript编写的OpenJScad来构建3D模型。
我试图弄清楚如何构造我的代码，以便我可以访问使用用户输入参数动态创建的对象的实例属性。我有一个父类Gear类，其中包含以下变量......
// Gear parent class
Gear = function(numTeeth, circularPitch, pressureAngle, clearance, thickness)
{
var pitchRadius = numTeeth * circularPitch / (2 * Math.PI);
我正在制作几个接受用户参数的Gear子类，即......
// Spur Gear
function makeSpur(params)
{
var gear = new Gear(
params.spurTeeth,
params.circularPitch,
params.pressureAngle,
params.clearance,
params.inputBore
);
if(params.inputBore > 0)
{
var inputBore = CSG.cylinder({start: [0,0,-params.thickness2], end:
[0,0,params.thickness2], radius: params.inputBore, resolution: 16});
gear = gear.subtract(inputBore).rotateX(90);
}
return gear;
...然后根据另一个Gear对象的pitchRadius属性动态生成位置坐标...
// function main
var spurGear = makeSpur(params);
spurGear = spurGear.translate([-pinionGear.pitchRadius,0,0]);
所有渲染，除非我尝试从另一个Gear实例访问pitchRadius属性。我已阅读有关原型和访问私有/公共属性的内容，但我无法弄清楚如何构造代码以便我可以访问函数main中的实例属性。
答案 0 :(得分：0)
这是完整的代码......
include("gears.jscad");
// Here we define the user editable parameters:
function getParameterDefinitions() {
return [
{ name: 'circularPitch', caption: 'Circular pitch:', type: 'float', initial: 5 },
{ name: 'pressureAngle', caption: 'Pressure angle:', type: 'float', initial: 20 },
{ name: 'clearance', caption: 'Clearance:', type: 'float', initial: 0 },
{ name: 'thickness', caption: 'Thickness of transmission gears:', type: 'float', initial: 5 },
{ name: 'spurTeeth', caption: 'Number of spur teeth:', type: 'int', initial: 32 },
{ name: 'pinionTeeth', caption: 'Number of pinion teeth:', type: 'int', initial: 14 },
{ name: 'bore', caption: 'Radius of shaft:', type: 'float', initial: 5 }
];
}
// Main function
function main(params)
{
// declare parts
spurGear = new makeSpur(params);
pinionGear = new makePinion(params);
// assemble parts
spurGear = spurGear.translate([-pinionGear.pitchRadius, 0, -20]); // BREAKS CODE
pinionGear = pinionGear.translate([-spurGear.pitchRadius, 0, 20]); // BREAKS CODE
return [spurGear,pinionGear];
}
// Spur Gear
function makeSpur(params)
{
var gear = new involuteGear(
params.spurTeeth,
params.circularPitch,
params.pressureAngle,
params.clearance,
params.thickness,
params.bore
);
if(params.bore > 0)
{
var bore = CSG.cylinder({start: [0,0,-params.thickness], end: [0,0,params.thickness], radius: params.bore, resolution: 16});
gear = gear.subtract(bore).rotateX(90);
}
return gear;
}
// Pinion Gear
function makePinion(params)
{
var gear = new involuteGear(
params.pinionTeeth,
params.circularPitch,
params.pressureAngle,
params.clearance,
params.thickness,
params.bore
);
if(params.bore > 0)
{
var bore = CSG.cylinder({start: [0,0,-params.thickness], end: [0,0,params.thickness], radius: params.bore, resolution: 16});
gear = gear.subtract(bore).rotateX(90);
}
return gear;
}
// title: Gear
// author: Joost Nieuwenhuijse
// license: MIT License
/*
For gear terminology see:
http://www.astronomiainumbria.org/advanced_internet_files/meccanica/easyweb.easynet.co.uk/_chrish/geardata.htm
Algorithm based on:
http://www.cartertools.com/involute.html
circularPitch: The distance between adjacent teeth measured at the pitch circle
*/
function involuteGear(numTeeth, circularPitch, pressureAngle, clearance, thickness)
{
// default values:
if(arguments.length < 3) pressureAngle = 20;
if(arguments.length < 4) clearance = 0;
if(arguments.length < 4) thickness = 1;
var addendum = circularPitch / Math.PI;
var dedendum = addendum + clearance;
// radiuses of the 4 circles:
this.pitchRadius = numTeeth * circularPitch / (2 * Math.PI);
// this.getpitchRadius = function() {
//return pitchRadius;
//};
var baseRadius = this.pitchRadius * Math.cos(Math.PI * pressureAngle / 180);
var outerRadius = this.pitchRadius + addendum;
var rootRadius = this.pitchRadius - dedendum;
var maxtanlength = Math.sqrt(outerRadius*outerRadius - baseRadius*baseRadius);
var maxangle = maxtanlength / baseRadius;
var tl_at_pitchcircle = Math.sqrt(this.pitchRadius*this.pitchRadius - baseRadius*baseRadius);
var angle_at_pitchcircle = tl_at_pitchcircle / baseRadius;
var diffangle = angle_at_pitchcircle - Math.atan(angle_at_pitchcircle);
var angularToothWidthAtBase = Math.PI / numTeeth + 2*diffangle;
// build a single 2d tooth in the 'points' array:
var resolution = 5;
var points = [new CSG.Vector2D(0,0)];
for(var i = 0; i <= resolution; i++)
{
// first side of the tooth:
var angle = maxangle * i / resolution;
var tanlength = angle * baseRadius;
var radvector = CSG.Vector2D.fromAngle(angle);
var tanvector = radvector.normal();
var p = radvector.times(baseRadius).plus(tanvector.times(tanlength));
points[i+1] = p;
// opposite side of the tooth:
radvector = CSG.Vector2D.fromAngle(angularToothWidthAtBase - angle);
tanvector = radvector.normal().negated();
p = radvector.times(baseRadius).plus(tanvector.times(tanlength));
points[2 * resolution + 2 - i] = p;
}
// create the polygon and extrude into 3D:
var tooth3d = new CSG.Polygon2D(points).extrude({offset: [0, 0, thickness]});
var allteeth = new CSG();
for(var j = 0; j < numTeeth; j++)
{
var ang = j*360/numTeeth;
var rotatedtooth = tooth3d.rotateZ(ang);
allteeth = allteeth.unionForNonIntersecting(rotatedtooth);
}
// build the root circle:
points = [];
var toothAngle = 2 * Math.PI / numTeeth;
var toothCenterAngle = 0.5 * angularToothWidthAtBase;
for(var k = 0; k < numTeeth; k++)
{
var angl = toothCenterAngle + k * toothAngle;
var p1 = CSG.Vector2D.fromAngle(angl).times(rootRadius);
points.push(p1);
}
// create the polygon and extrude into 3D:
var rootcircle = new CSG.Polygon2D(points).extrude({offset: [0, 0, thickness]});
var result = rootcircle.union(allteeth);
// center at origin:
result = result.translate([0, 0, -thickness/2]);
return result;
}
答案 1 :(得分：0)
我注意到您实际上是在构造函数中返回CSG对象，因此请尝试使用OpenJSCAD用户指南中描述的属性容器。根据指南属性变量旨在存储对象的元数据。
这是指南中的一个例子：
var cube = CSG.cube({radius: 1.0});
cube.properties.aCorner = new CSG.Vector3D([1, 1, 1]);
补充意见：