opencascade绘制实体消影线

如图，利用opencascade绘制出给定视角的齿轮的消隐线；

OCC提供了两种算法，来绘制消隐线， 帮助文档介绍如下：

算法建立过程：

给出实现代码：

void getOutLine()
{
	//获取鼠标选中模型的那个对象  
	TopoDS_Shape detectShape = m_context->DetectedShape();

	//进行模型网格离散化
	BRepMesh_IncrementalMesh aMesher(detectShape, 0.1);

	//消隐线算法初始化
	Handle_HLRBRep_PolyAlgo aHlrPolyAlgo = new HLRBRep_PolyAlgo();

	//定义观察坐标系
	gp_Ax2 ax2(gp_Pnt(0, 0, 0), gp_Dir(10, 1, 1), gp_Dir(1, 0, 0));
	HLRAlgo_Projector aProjector(ax2);

	//消隐算法建立
	aHlrPolyAlgo->Load(detectShape);
	aHlrPolyAlgo->Projector(aProjector);
	aHlrPolyAlgo->Update();

	//消隐形状转化
	HLRBRep_PolyHLRToShape aHlr2Shape;
	aHlr2Shape.Update(aHlrPolyAlgo);
	TopoDS_Shape visual_shape = aHlr2Shape.VCompound();

	//遍历拓扑形状进行显示
	for (TopExp_Explorer e(visual_shape, TopAbs_EDGE); e.More(); e.Next())
	{
		TopoDS_Edge anEdge = TopoDS::Edge(e.Current());
		Handle(AIS_Shape)ais_shape = new AIS_Shape(anEdge);

		//设置消隐类型
		//ais_shape->SetTypeOfHLR(Prs3d_TOH_Algo);
		//ais_shape->SetTypeOfHLR(Prs3d_TOH_NotSet); 
		ais_shape->SetTypeOfHLR(Prs3d_TOH_PolyAlgo);

		m_context->Display(ais_shape, Standard_True);
		m_view->FitAll();
	}
}