OCC瓶子案例

对于OCC的第一个案例，对个别不懂得API做了一些注释，其中螺纹部分比较难理解，这里可以参考本地OCC安装目录下得html去看这个例子：file:///C:/OpenCASCADE-7.6.0-vc14-64/opencascade-7.6.0/doc/overview/html

如果没有也可看这篇博文（欢迎讨论）：

OpenCasCade 教程-瓶子](https://blog.csdn.net/hoya5121/article/details/4297678?spm=1001.2014.3001.5502)

// Profile : Define Support Points
	gp_Pnt aPnt1(-myWidth / 2., 0, 0);
	gp_Pnt aPnt2(-myWidth / 2., -myThickness / 4., 0);
	gp_Pnt aPnt3(0, -myThickness / 2., 0);
	gp_Pnt aPnt4(myWidth / 2., -myThickness / 4., 0);
	gp_Pnt aPnt5(myWidth / 2., 0, 0);
	// Profile : Define the Geometry
	Handle(Geom_TrimmedCurve) anArcOfCircle = GC_MakeArcOfCircle(aPnt2, aPnt3, aPnt4);
	Handle(Geom_TrimmedCurve) aSegment1 = GC_MakeSegment(aPnt1, aPnt2);
	Handle(Geom_TrimmedCurve) aSegment2 = GC_MakeSegment(aPnt4, aPnt5);
	// Profile : Define the Topology
	TopoDS_Edge anEdge1 = BRepBuilderAPI_MakeEdge(aSegment1);
	TopoDS_Edge anEdge2 = BRepBuilderAPI_MakeEdge(anArcOfCircle);
	TopoDS_Edge anEdge3 = BRepBuilderAPI_MakeEdge(aSegment2);
	TopoDS_Wire aWire = BRepBuilderAPI_MakeWire(anEdge1, anEdge2, anEdge3);
	// Complete Profile
	gp_Ax1 xAxis = gp::OX();
	gp_Trsf aTrsf;
	aTrsf.SetMirror(xAxis);
	BRepBuilderAPI_Transform aBRepTrsf(aWire, aTrsf);
	TopoDS_Shape aMirroredShape = aBRepTrsf.Shape();
	TopoDS_Wire aMirroredWire = TopoDS::Wire(aMirroredShape);
	BRepBuilderAPI_MakeWire mkWire;
	mkWire.Add(aWire);
	mkWire.Add(aMirroredWire);
	TopoDS_Wire myWireProfile = mkWire.Wire();
	// Body : Prism the Profile
	TopoDS_Face myFaceProfile = BRepBuilderAPI_MakeFace(myWireProfile);
	gp_Vec aPrismVec(0, 0, myHeight);
	TopoDS_Shape myBody = BRepPrimAPI_MakePrism(myFaceProfile, aPrismVec);

	// Body : Apply Fillets
	BRepFilletAPI_MakeFillet mkFillet(myBody);

	TopExp_Explorer anEdgeExplorer(myBody, TopAbs_EDGE);
	while (anEdgeExplorer.More())
	{
		TopoDS_Edge anEdge = TopoDS::Edge(anEdgeExplorer.Current());
		// Add edge to fillet algorithm
		mkFillet.Add(myThickness / 12., anEdge);
		anEdgeExplorer.Next();
	}
	myBody = mkFillet.Shape();
	// Body : Add the Neck
	gp_Pnt neckLocation(0, 0, myHeight);
	gp_Dir neckAxis = gp::DZ();
	gp_Ax2 neckAx2(neckLocation, neckAxis);
	Standard_Real myNeckRadius = myThickness / 4.;
	Standard_Real myNeckHeight = myHeight / 10.;
	BRepPrimAPI_MakeCylinder MKCylinder(neckAx2, myNeckRadius, myNeckHeight);
	TopoDS_Shape myNeck = MKCylinder.Shape();
	myBody = BRepAlgoAPI_Fuse(myBody, myNeck);

	// Body : Create a Hollowed Solid
	TopoDS_Face facetoRemove;
	Standard_Real zMax = -1;
	for (TopExp_Explorer aFaceExplorer(myBody, TopAbs_FACE); aFaceExplorer.More(); aFaceExplorer.Next())
	{
		TopoDS_Face aFace = TopoDS::Face(aFaceExplorer.Current());
		// Check if <aFace> is the top face of the bottle's neck
		Handle(Geom_Surface) aSurface = BRep_Tool::Surface(aFace);
		//DynamicType方法：可以得出对象的实际类型,但是要用它和已知类型比较来得出aSurface是一个平面，还是一个园柱侧面或其它类型；
		//为了用所给定的类型和要找的类型相比较，可以使用STANDARD_TYPE宏,这个宏返回一个类的类型:
		if (aSurface->DynamicType() == STANDARD_TYPE(Geom_Plane)) //只要平面
		{
			Handle(Geom_Plane) aPlane = Handle(Geom_Plane)::DownCast(aSurface);
			gp_Pnt aPnt = aPlane->Location();//面原始点
			Standard_Real aZ = aPnt.Z();
			if (aZ > zMax)
			{
				zMax = aZ;
				facetoRemove = aFace;
			}
		}
	}
	TopTools_listofShape facesToRemove;
	facesToRemove.Append(facetoRemove);
	BRepOffsetAPI_MakeThickSolid BodyMaker;
	BodyMaker.MakeThickSolidByJoin(myBody, facesToRemove, -myThickness / 50, 1.e-3);
	myBody = BodyMaker.Shape();
	// Threading : Create Surfaces
	Handle(Geom_CylindricalSurface) aCyl1 = new Geom_CylindricalSurface(neckAx2, myNeckRadius * 0.99);
	Handle(Geom_CylindricalSurface) aCyl2 = new Geom_CylindricalSurface(neckAx2, myNeckRadius * 1.05);
	// Threading : Define 2D Curves
	gp_Pnt2d aPnt(2. * M_PI, myNeckHeight / 2.);
	gp_Dir2d aDir(2. * M_PI, myNeckHeight / 4.);
	gp_Ax2d anAx2d(aPnt, aDir);
	Standard_Real aMajor = 2. * M_PI;
	Standard_Real aMinor = myNeckHeight / 10;
	Handle(Geom2d_Ellipse) anEllipse1 = new Geom2d_Ellipse(anAx2d, aMajor, aMinor);
	Handle(Geom2d_Ellipse) anEllipse2 = new Geom2d_Ellipse(anAx2d, aMajor, aMinor / 4);
	//参数限制在0-PI之间
	Handle(Geom2d_TrimmedCurve) anArc1 = new Geom2d_TrimmedCurve(anEllipse1, 0, M_PI);
	Handle(Geom2d_TrimmedCurve) anArc2 = new Geom2d_TrimmedCurve(anEllipse2, 0, M_PI);
	//最后一步包括定义线段，这对于两条曲线是相同的：一条线受其中一个圆弧的第一点和最后一个点的限制
	//要访问与曲线或曲面的参数相对应的点，请使用 Value 或 D0 方法（表示 0阶导数），
	gp_Pnt2d anEllipsePnt1 = anEllipse1->Value(0);
	gp_Pnt2d anEllipsePnt2 = anEllipse1->Value(M_PI);
	Handle(Geom2d_TrimmedCurve) aSegment = GCE2d_MakeSegment(anEllipsePnt1, anEllipsePnt2);


	// Threading : Build Edges and Wires
	TopoDS_Edge anEdge1OnSurf1 = BRepBuilderAPI_MakeEdge(anArc1, aCyl1);
	TopoDS_Edge anEdge2OnSurf1 = BRepBuilderAPI_MakeEdge(aSegment, aCyl1);
	TopoDS_Edge anEdge1OnSurf2 = BRepBuilderAPI_MakeEdge(anArc2, aCyl2);
	TopoDS_Edge anEdge2OnSurf2 = BRepBuilderAPI_MakeEdge(aSegment, aCyl2);
	TopoDS_Wire threadingWire1 = BRepBuilderAPI_MakeWire(anEdge1OnSurf1, anEdge2OnSurf1);
	TopoDS_Wire threadingWire2 = BRepBuilderAPI_MakeWire(anEdge1OnSurf2, anEdge2OnSurf2);

	//OsgBuild::disPlay(threadingWire1);
	//OsgBuild::disPlay(threadingWire2);

	BRepLib::BuildCurves3d(threadingWire1);
	BRepLib::BuildCurves3d(threadingWire2);//计算wire的形状
	// Create Threading
	BRepOffsetAPI_ThruSections aTool(Standard_True); //根据两线放样创建封闭实体
	aTool.AddWire(threadingWire1);
	aTool.AddWire(threadingWire2);
	aTool.CheckCompatibility(Standard_False); //设置是否激活检测网格是否有相同的边的选项。
	TopoDS_Shape myThreading = aTool.Shape();
	// Building the Resulting Compound
	TopoDS_Compound aRes;
	BRep_Builder aBuilder;
	aBuilder.MakeCompound(aRes);
	aBuilder.Add(aRes, myBody);
	aBuilder.Add(aRes, myThreading);
	return aRes;