首先定义了一些基本的几何元素,如线、圆和平面,然后使用makeExtrudebydir
函数来对一个面进行挤出操作。下面是详细过程:
定义Extrude函数:makeExtrudebydir函数接受一个TopoDS_Shape对象和一个gp_Vec对象作为参数。TopoDS_Shape是OCCT中用于表示所有拓扑实体的基类,而gp_Vec是表示三维向量的类。函数首先检查输入的形状类型,如果是线(TopAbs_WIRE),则将其转换为面(BRepBuilderAPI_MakeFace),因为挤出操作需要一个面作为基础。
执行Extrude操作:如果输入的形状是面,那么使用BRepPrimAPI_MakePrism类来执行挤出操作。这个类需要两个参数:基础面和挤出方向的向量。函数创建了BRepPrimAPI_MakePrism的实例,并将基础面和挤出方向传递给它,从而生成挤出后的三维形状。
异常处理:函数中使用了try-catch块来捕获并处理可能出现的异常。如果发生Standard_Failure异常,将打印错误信息;如果发生其他未知异常,将打印一条通用错误消息。
创建几何元素:在main函数中,首先定义了一些点和平面,然后使用这些点创建了线和圆。接着,使用BRepBuilderAPI_MakeEdge和BRepBuilderAPI_MakeWire创建了边和线,最后使用BRepBuilderAPI_MakeFace创建了一个面。
创建视图并显示:使用Viewer类创建了一个视图,并将创建的线和挤出后的面添加到视图中。然后,启动消息循环以显示几何形状。
代码如下:
#include <TopoDS.hxx>
#include <gp_Ax3.hxx>
#include <BRepPrimAPI_MakePrism.hxx>
#include <GC_MakeSegment.hxx>
#include <BRepBuilderAPI_MakeEdge.hxx>
#include <gp_Circ.hxx>
#include <gp_Pln.hxx>
#include <BRepBuilderAPI_MakeFace.hxx>
#include <GC_MakeCircle.hxx>
#include <BRepBuilderAPI_MakeWire.hxx>
#include <BRepOffsetAPI_MakePipe.hxx>
#include <GC_MakeArcOfCircle.hxx>
#include <gp_GTrsf.hxx>
#include <BRepBuilderAPI_Transform.hxx>
#include"Viewer.h"
TopoDS_Shape makeExtrudebydir(const TopoDS_Shape& oriShape, const gp_Vec& dir)
{
TopoDS_Shape rstShape;
try
{
TopoDS_Shape oriShape1 = oriShape;
if (oriShape1.ShapeType() == TopAbs_WIRE)
oriShape1 = BRepBuilderAPI_MakeFace(TopoDS::Wire(oriShape1));
rstShape = BRepPrimAPI_MakePrism(oriShape1, dir);
}
catch (const Standard_Failure& err)
{
std::cout << "\nStandard_Failure: " << err.GetMessageString();
}
catch (...)
{
std::cout << "\nBRepPrimAPI_MakePrism some unknown errors occur";
}
return rstShape;
}
int main(int argc, char* argv[])
{
gp_Dir Z(0.0, 0.0, 1.0);
gp_Pnt center(0, 0, 0.0);
gp_Pnt xr(0.5, 0, 0.0);
gp_Pnt yr(0.0, 1.0, 0.0);
gp_Pnt zr(0.0, 0.0, 7.0);
gp_Ax2 wb(center, Z);
gp_Circ wbcircle(wb, 0.125 / 2);
TopoDS_Edge wbe = BRepBuilderAPI_MakeEdge(wbcircle);
TopoDS_Edge xline = BRepBuilderAPI_MakeEdge(center, xr);
TopoDS_Edge yline = BRepBuilderAPI_MakeEdge(center, yr);
TopoDS_Edge zline = BRepBuilderAPI_MakeEdge(center, zr);
gp_Pln aPlane;
gp_Circ aCircle1(gp::XOY(), 1.0);
gp_Circ aCircle2(gp::XOY(), 1.0);
gp_Circ aCircle3(gp::XOY(), 1.0);
aCircle1.SetLocation(gp_Pnt(3.0, 3.0, 0.0));
aCircle2.SetLocation(gp_Pnt(7.0, 3.0, 0.0));
aCircle3.SetLocation(gp_Pnt(3.0, 7.0, 0.0));
BRepBuilderAPI_MakeEdge anEdgeMaker1(aCircle1);
BRepBuilderAPI_MakeEdge anEdgeMaker2(aCircle2);
BRepBuilderAPI_MakeEdge anEdgeMaker3(aCircle3);
BRepBuilderAPI_MakeWire aWireMaker1(anEdgeMaker1.Edge());
BRepBuilderAPI_MakeWire aWireMaker2(anEdgeMaker2.Edge());
BRepBuilderAPI_MakeWire aWireMaker3(anEdgeMaker3.Edge());
BRepBuilderAPI_MakeFace aFaceMaker(aPlane, 0.0, 10.0, 0.0, 10.0);
Viewer vout(50, 50, 500, 500);
vout << wbe;
vout << xline;
vout << yline;
vout << zline;
vout << makeExtrudebydir(aFaceMaker, gp_Vec(1,3,5));
vout.StartMessageLoop();
return 0;
}