void showStlModel(const std::string& modelPath){
vtkSmartPointer<vtkSTLReader> stlReader = vtkSmartPointer<vtkSTLReader>::New();
stlReader->SetFileName(modelPath.c_str());//modelPath是stl模型在電腦裡面的存儲路徑
stlReader->Update();
if (!_cellLocator) {
_cellLocator = vtkSmartPointer<vtkCellLocator>::New();
}
_cellLocator->SetDataSet(stlReader->GetOutput());
_cellLocator->BuildLocator();
if (!_stlModel) {
_stlModel = vtkSmartPointer<vtkPolyData>::New();
}
_stlModel = stlReader->GetOutput();
auto normals = vtkSmartPointer<vtkTriangleMeshPointNormals>::New();
normals->SetInputData(_stlModel);
normals->Update();
_stlModel = normals->GetOutput();
auto modelMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
_modelActor->SetMapper(modelMapper);
modelMapper->SetInputConnection(stlReader->GetOutputPort());
_qvtkWidget->GetRenderWindow()->Render();
}