实现剪裁需要三步：
输入被剪裁模型； 被剪裁数据一般有： 影像（vti/vtr格式 dcm/图片/矩阵 等数据）、 模型（vtp/vtu格式 stl/obj/体网格 等数据）、 场景
剪切区域选择（交互）； vtk提供大量现成的交互vtkWidget。可以自己开发交互，我只搞过一个，很麻烦。现成的虽然丑点但是是很多前辈积累的，比较实用。一般不建议自己开发。跟剪切相关的，遵循kiss原则，大家直接想到的无非就是： 平面上任意点两个点，模型分成两个部分 平面上任意点多个点，练成闭合样条曲线，分成曲线内、曲线外 空间放置一个球，分成球内求外 空间放置一个立方体，截取立方体内外
剪切算法实现。 模型的基本上是自己搞一个无限长的平面，利用在利用现成的与或非 影像的话vtkExtractVOI可以实现任意剪裁
临时搞一个demo，可以先看下效果。
被剪裁模型：
本地stl文件剪切区域选择：
球、box、平面任意两点、平面任意多点剪切算法：
vtkClipPolyData实现两个模型取并、vtkClipPolyData实现两个模型取异、vtkCutter实现两个模型去交线、vtkBoxClipDataSet生成无限平面后去并stl、box、取交集stl、box、取外部stl、box、取交线stl、ball、取交集
stl、ball、取外部
stl、平面直线、取最大连通域（直线设置比较细，录屏压缩后看不到了）
stl、平面多点、取最大连通域（顺时针内、逆时针外）
vtkWidget 大部分使用方法基本一样，vtkBoxWidget举例
1 初始化
if (widget_type_ == BOX) { if (clip_box_widget_ == nullptr) { clip_box_widget_ = vtkSmartPointer<vtkBoxWidget>::New(); clip_box_widget_->GetFaceProperty()->SetColor(0.6, 0.6, 0.2); clip_box_widget_->GetFaceProperty()->SetOpacity(0.25); clip_box_widget_->SetInteractor( vmtk_renderer_->GetRenderWindowInteractor()); } }1 设置rans
clip_box_widget_->GetTransform(transform_);2 开启交互
if (widget_type_ == BOX) { clip_box_widget_->SetInputData(surface_); clip_box_widget_->PlaceWidget(); } else if (widget_type_ == SPHERE) { } else if (widget_type_ == LINE) { } if (transform_ && widget_type_ == BOX) { clip_box_widget_->SetTransform(transform_); clip_box_widget_->On(); }3 交互完成后获取数据
vtkSmartPointer<vtkClipPolyData> clipper = vtkSmartPointer<vtkClipPolyData>::New(); vtkSmartPointer<vtkPlanes> clip_planes_function; vtkSmartPointer<vtkSphere> clip_sphere_function; clipper->SetInputData(surface_); clipper->GenerateClippedOutputOn(); clipper->SetInsideOut(inside_out_); if (widget_type_ == BOX) { clip_planes_function = vtkSmartPointer<vtkPlanes>::New(); clipper->SetClipFunction(clip_planes_function); } else if (widget_type_ == SPHERE) { clip_sphere_function = vtkSmartPointer<vtkSphere>::New(); clipper->SetClipFunction(clip_sphere_function); } vtkSmartPointer<vtkCutter> cutter = vtkSmartPointer<vtkCutter>::New(); cutter->SetInputData(surface_); if (widget_type_ == BOX) { cutter->SetCutFunction(clip_planes_function); } else if (widget_type_ == SPHERE) { cutter->SetCutFunction(clip_sphere_function); } clipped_surface_ = vtkSmartPointer<vtkPolyData>::New(); cut_lines_ = vtkSmartPointer<vtkPolyData>::New(); if (widget_type_ == BOX) { clip_box_widget_->GetPlanes(clip_planes_function); } else if (widget_type_ == SPHERE) { clip_sphere_widget_->GetSphere(clip_sphere_function); } clipper->Update(); if (widget_type_ == BOX) { clip_box_widget_->Off(); } else if (widget_type_ == SPHERE) { clip_sphere_widget_->Off(); } cutter->Update();4 关闭交互
if (widget_type_ == BOX) { clip_box_widget_->Off(); } else if (widget_type_ == SPHERE) { clip_sphere_widget_->Off(); }完整代码
我这里把vtkSeedWidget、vtkBoxWidget、vtkSphereWidget封装在一起。
#ifndef VMTKSURFACECLIPPER_H #define VMTKSURFACECLIPPER_H #include <QObject> #include <QPointer> #include "vmtkrenderer.h" #include <vtkPolyData.h> #include <vtkTransform.h> #include <vtkBoxWidget.h> #include <vtkSeedWidget.h> #include <vtkSmartPointer.h> #include <vtkSphereWidget.h> class SurfaceClipper : public QObject { Q_OBJECT public: enum WidgetType {// 切割方式 BOX, SPHERE, LINE }; public: explicit SurfaceClipper(QObject *parent = nullptr); virtual ~SurfaceClipper() override; void Execute(); void SetEnable(const bool value); void SetSurface(const vtkSmartPointer<vtkPolyData> value); void SetWidgetType(const WidgetType value); void SetTransform(const vtkSmartPointer<vtkTransform> value); void SetInsideOut(const bool value); void SetVmtkRenderer(const QPointer<VmtkRenderer> value); vtkSmartPointer<vtkPolyData> GetSurface() const; vtkSmartPointer<vtkPolyData> GetClippedSurface() const; vtkSmartPointer<vtkPolyData> GetCutLines() const; vtkSmartPointer<vtkTransform> GetTransForm() const; Q_SIGNALS: void SignalClippedFinish(); private: void Initial(); void Display(); void ClipCallback(); private Q_SLOTS: void SlotKeyPressed(const QString &key); void SlotSeedChanged(vtkObject *caller, unsigned long vtk_event, void *client_data, void *call_data); private: bool first_connect_; bool own_renderer_; bool inside_out_; QPointer<VmtkRenderer> vmtk_renderer_; vtkSmartPointer<vtkPolyData> surface_; vtkSmartPointer<vtkPolyData> clipped_surface_; vtkSmartPointer<vtkPolyData> cut_lines_; vtkSmartPointer<vtkEventQtSlotConnect> vtk_connections_; vtkSmartPointer<vtkSeedWidget> seed_widget_; vtkSmartPointer<vtkBoxWidget> clip_box_widget_; vtkSmartPointer<vtkSphereWidget> clip_sphere_widget_; vtkSmartPointer<vtkTransform> transform_; WidgetType widget_type_; }; #endif // VMTKSURFACECLIPPER_H #include "vmtksurfaceclipper.h" #include <QDebug> #include <vtkPoints.h> #include <vtkCamera.h> #include <vtkCutter.h> #include <vtkPlanes.h> #include <vtkSphere.h> #include <vtkStripper.h> #include <vtkProperty.h> #include <vtkPointData.h> #include <vtkProperty2D.h> #include <vtkClipPolyData.h> #include <vtkContourFilter.h> #include <vtkCleanPolyData.h> #include <vtkPolyDataMapper.h> #include <vtkBoxClipDataSet.h> #include <vtkSeedRepresentation.h> #include <vtkDataSetSurfaceFilter.h> #include <vtkPolyDataConnectivityFilter.h> #include <vtkPointHandleRepresentation2D.h> SurfaceClipper::SurfaceClipper(QObject *parent) : QObject(parent) { Initial(); } SurfaceClipper::~SurfaceClipper() { if (own_renderer_) { vmtk_renderer_->deleteLater(); } } /** * @brief SurfaceClipper::Execute * ui交互开启 */ void SurfaceClipper::Execute() { qDebug(); if (surface_ == nullptr) { qWarning() << "no Surface"; return ; } if (vmtk_renderer_ == nullptr) { vmtk_renderer_ = new VmtkRenderer(); vmtk_renderer_->Initialize(); own_renderer_ = true; } if (widget_type_ == BOX) { if (clip_box_widget_ == nullptr) { clip_box_widget_ = vtkSmartPointer<vtkBoxWidget>::New(); clip_box_widget_->GetFaceProperty()->SetColor(0.6, 0.6, 0.2); clip_box_widget_->GetFaceProperty()->SetOpacity(0.25); clip_box_widget_->SetInteractor( vmtk_renderer_->GetRenderWindowInteractor()); } } else if (widget_type_ == SPHERE) { if (clip_sphere_widget_ == nullptr) { clip_sphere_widget_ = vtkSmartPointer<vtkSphereWidget>::New(); clip_sphere_widget_->GetSphereProperty()->SetColor(0.6, 0.6, 0.2); clip_sphere_widget_->GetSphereProperty()->SetOpacity(0.25); clip_sphere_widget_->GetSelectedSphereProperty() ->SetColor(0.6, 0.0, 0.0); clip_sphere_widget_->GetSelectedSphereProperty() ->SetOpacity(0.75); clip_sphere_widget_->SetRepresentationToSurface(); clip_sphere_widget_->SetPhiResolution(20); clip_sphere_widget_->SetThetaResolution(20); clip_sphere_widget_->SetInteractor( vmtk_renderer_->GetRenderWindowInteractor()); } } else if (widget_type_ == LINE) { if (this->seed_widget_ == nullptr) { this->seed_widget_ = vtkSmartPointer<vtkSeedWidget>::New(); vtkNew<vtkPointHandleRepresentation2D> handle_rep; handle_rep->GetProperty()->SetColor(1, 0, 0); vtkNew<vtkSeedRepresentation> widget_rep; widget_rep->SetHandleRepresentation(handle_rep); this->seed_widget_->SetInteractor( this->vmtk_renderer_->GetRenderWindowInteractor()); this->seed_widget_->SetRepresentation(widget_rep); } qint32 num_seeds = this->seed_widget_->GetSeedRepresentation()->GetNumberOfSeeds(); for (qint32 i = 0; i < num_seeds; ++i) { this->seed_widget_->GetSeedRepresentation()->RemoveLastHandle(); this->seed_widget_->DeleteSeed( this->seed_widget_->GetSeedRepresentation()->GetNumberOfSeeds()); } } if (first_connect_) { connect(vmtk_renderer_, &VmtkRenderer::SignalKeyPressed, this, &SurfaceClipper::SlotKeyPressed); this->vtk_connections_ = vtkSmartPointer<vtkEventQtSlotConnect>::New(); vtk_connections_->Connect(seed_widget_, vtkCommand::PlacePointEvent, this, SLOT(SlotSeedChanged(vtkObject *, unsigned long, void *, void *))); first_connect_ = false; } transform_ = vtkSmartPointer<vtkTransform>::New(); if (widget_type_ == BOX) { clip_box_widget_->GetTransform(transform_); } Display(); if (own_renderer_) { vmtk_renderer_->Deallocate(); } } /** * @brief SurfaceClipper::SetSurface * 设置输入模型 * @param value */ void SurfaceClipper::SetSurface(const vtkSmartPointer<vtkPolyData> value) { surface_ = value; } /** * @brief SurfaceClipper::SetWidgetType * 设置切割方式 * @param value */ void SurfaceClipper::SetWidgetType(const SurfaceClipper::WidgetType value) { widget_type_ = value; } /** * @brief SurfaceClipper::SetTransform * 设置Trans转换 * @param value */ void SurfaceClipper::SetTransform(const vtkSmartPointer<vtkTransform> value) { transform_ = value; } /** * @brief SurfaceClipper::SetInsideOut * 设置是否取反 * @param value */ void SurfaceClipper::SetInsideOut(const bool value) { inside_out_ = value; } /** * @brief SurfaceClipper::SetVmtkRenderer * 输入Renderer * @param value */ void SurfaceClipper::SetVmtkRenderer(const QPointer<VmtkRenderer> value) { vmtk_renderer_ = value; } /** * @brief SurfaceClipper::GetSurface * 获取剪切后模型（交） * @return */ vtkSmartPointer<vtkPolyData> SurfaceClipper::GetSurface() const { return surface_; } /** * @brief SurfaceClipper::GetClippedSurface * 获取剪切后模型（异） * @return */ vtkSmartPointer<vtkPolyData> SurfaceClipper::GetClippedSurface() const { return clipped_surface_; } /** * @brief SurfaceClipper::GetCutLines * 获取剪切后交线 * @return */ vtkSmartPointer<vtkPolyData> SurfaceClipper::GetCutLines() const { return cut_lines_; } /** * @brief SurfaceClipper::GetTransForm * BOX模式剪切转换 * @return */ vtkSmartPointer<vtkTransform> SurfaceClipper::GetTransForm() const { return transform_; } /** * @brief SurfaceClipper::Initial * 初始化 */ void SurfaceClipper::Initial() { surface_ = nullptr; clipped_surface_ = nullptr; cut_lines_ = nullptr; vmtk_renderer_ = nullptr; clip_box_widget_ = nullptr; clip_sphere_widget_ = nullptr; first_connect_ = true; own_renderer_ = false; transform_ = nullptr; widget_type_ = LINE; inside_out_ = true; setObjectName("vmtksurfaceclipper"); } /** * @brief SurfaceClipper::Display * 开启widget */ void SurfaceClipper::Display() { if (widget_type_ == BOX) { clip_box_widget_->SetInputData(surface_); clip_box_widget_->PlaceWidget(); } else if (widget_type_ == SPHERE) { clip_sphere_widget_->SetInputData(surface_); clip_sphere_widget_->PlaceWidget(); clip_sphere_widget_->On(); } else if (widget_type_ == LINE) { this->seed_widget_->On(); } if (transform_ && widget_type_ == BOX) { clip_box_widget_->SetTransform(transform_); clip_box_widget_->On(); } vmtk_renderer_->Render(); } /** * @brief SurfaceClipper::ClipCallback * 剪裁函数 */ void SurfaceClipper::ClipCallback() { qDebug(); if ((widget_type_ == BOX && clip_box_widget_->GetEnabled() != 1) || (widget_type_ == SPHERE && clip_sphere_widget_->GetEnabled() != 1)) { return ; } if(widget_type_ == LINE) { if (this->seed_widget_->GetSeedRepresentation()->GetNumberOfSeeds() != 2 || this->surface_ == nullptr) { return ; } double pos1[3], pos2[3]; this->seed_widget_->GetSeedRepresentation()->GetSeedWorldPosition(0, pos1); this->seed_widget_->GetSeedRepresentation()->GetSeedWorldPosition(1, pos2); this->seed_widget_->Off(); QList<QList<double>> pts = { {0, 0, 0}, {1, 0, 0}, {1, 1, 0}, {0, 1, 0}, {0, 0, 1}, {1, 0, 1}, {1, 1, 1}, {0, 1, 1} }; vtkNew<vtkPoints> points; for (qint32 i = 0; i < pts.size(); ++i) { points->InsertPoint(i, pts[i][0], pts[i][1], pts[i][2]); } double direction[3]; this->vmtk_renderer_->GetRenderer()->GetActiveCamera() ->GetDirectionOfProjection(direction); points->SetPoint(0, pos1[0] - direction[0] * 1000, pos1[1] - direction[1] * 1000, pos1[2] - direction[2] * 1000); points->SetPoint(3, pos1[0] + direction[0] * 1000, pos1[1] + direction[1] * 1000, pos1[2] + direction[2] * 1000); points->SetPoint(1, pos2[0] - direction[0] * 1000, pos2[1] - direction[1] * 1000, pos2[2] - direction[2] * 1000); points->SetPoint(2, pos2[0] + direction[0] * 1000, pos2[1] + direction[1] * 1000, pos2[2] + direction[2] * 1000); double direction2[3], direction_offset[3]; direction2[0] = pos1[0] - pos2[0]; direction2[1] = pos1[1] - pos2[1]; direction2[2] = pos1[2] - pos2[2]; vtkMath::Cross(direction, direction2, direction_offset); points->SetPoint(4, pos1[0] - direction[0] * 1000 + direction_offset[0] * 0.01, pos1[1] - direction[1] * 1000 + direction_offset[1] * 0.01, pos1[2] - direction[2] * 1000 + direction_offset[2] * 0.01); points->SetPoint(7, pos1[0] + direction[0] * 1000 + direction_offset[0] * 0.01, pos1[1] + direction[1] * 1000 + direction_offset[1] * 0.01, pos1[2] + direction[2] * 1000 + direction_offset[2] * 0.01); points->SetPoint(5, pos2[0] - direction[0] * 1000 + direction_offset[0] * 0.01, pos2[1] - direction[1] * 1000 + direction_offset[1] * 0.01, pos2[2] - direction[2] * 1000 + direction_offset[2] * 0.01); points->SetPoint(6, pos2[0] + direction[0] * 1000 + direction_offset[0] * 0.01, pos2[1] + direction[1] * 1000 + direction_offset[1] * 0.01, pos2[2] + direction[2] * 1000 + direction_offset[2] * 0.01); vtkNew<vtkBoxClipDataSet> box_clip; box_clip->SetInputData(this->surface_); box_clip->GenerateClippedOutputOn(); double n0[3], n1[3], n2[3], n3[3], n4[3], n5[3]; double p0[3], p1[3], p2[3], p3[3], p4[3], p5[3]; double pt0[3], pt1[3], pt2[3], pt3[3], pt4[3], pt5[3], pt6[3], pt7[3]; points->GetPoint(0, pt0); points->GetPoint(1, pt1); points->GetPoint(2, pt2); points->GetPoint(3, pt3); points->GetPoint(4, pt4); points->GetPoint(5, pt5); points->GetPoint(6, pt6); points->GetPoint(7, pt7); for (qint32 i = 0; i < 3; ++i) { p0[i] = (pt1[i] + pt3[i]) / 2; n0[i] = (pt1[i] - pt5[i]); p1[i] = (pt5[i] + pt7[i]) / 2; n1[i] = (pt5[i] - pt1[i]); p2[i] = (pt2[i] + pt5[i]) / 2; n2[i] = (pt5[i] - pt4[i]); p3[i] = (pt3[i] + pt4[i]) / 2; n3[i] = (pt4[i] - pt5[i]); p4[i] = (pt0[i] + pt5[i]) / 2; n4[i] = (pt5[i] - pt6[i]); p5[i] = (pt2[i] + pt7[i]) / 2; n5[i] = (pt6[i] - pt5[i]); } box_clip->SetBoxClip(n0, p0, n1, p1, n2, p2, n3, p3, n4, p4, n5, p5); vtkNew<vtkDataSetSurfaceFilter> surface_in; surface_in->SetInputConnection(box_clip->GetOutputPort(0)); vtkNew<vtkDataSetSurfaceFilter> surface_out; surface_out->SetInputConnection(box_clip->GetOutputPort(1)); vtkNew<vtkPolyDataConnectivityFilter> connectivity_filter; connectivity_filter->SetInputConnection(surface_out->GetOutputPort()); connectivity_filter->SetExtractionModeToLargestRegion(); connectivity_filter->Update(); this->surface_ = connectivity_filter->GetOutput(); return; } vtkSmartPointer<vtkClipPolyData> clipper = vtkSmartPointer<vtkClipPolyData>::New(); vtkSmartPointer<vtkPlanes> clip_planes_function; vtkSmartPointer<vtkSphere> clip_sphere_function; clipper->SetInputData(surface_); clipper->GenerateClippedOutputOn(); clipper->SetInsideOut(inside_out_); if (widget_type_ == BOX) { clip_planes_function = vtkSmartPointer<vtkPlanes>::New(); clipper->SetClipFunction(clip_planes_function); } else if (widget_type_ == SPHERE) { clip_sphere_function = vtkSmartPointer<vtkSphere>::New(); clipper->SetClipFunction(clip_sphere_function); } vtkSmartPointer<vtkCutter> cutter = vtkSmartPointer<vtkCutter>::New(); cutter->SetInputData(surface_); if (widget_type_ == BOX) { cutter->SetCutFunction(clip_planes_function); } else if (widget_type_ == SPHERE) { cutter->SetCutFunction(clip_sphere_function); } clipped_surface_ = vtkSmartPointer<vtkPolyData>::New(); cut_lines_ = vtkSmartPointer<vtkPolyData>::New(); if (widget_type_ == BOX) { clip_box_widget_->GetPlanes(clip_planes_function); } else if (widget_type_ == SPHERE) { clip_sphere_widget_->GetSphere(clip_sphere_function); } clipper->Update(); if (widget_type_ == BOX) { clip_box_widget_->Off(); } else if (widget_type_ == SPHERE) { clip_sphere_widget_->Off(); } cutter->Update(); cut_lines_->DeepCopy(cutter->GetOutput()); surface_->DeepCopy(clipper->GetOutput()); clipped_surface_->DeepCopy(clipper->GetClippedOutput()); } /** * @brief SurfaceClipper::SlotKeyPressed * 键盘回调函数 * @param key */ void SurfaceClipper::SlotKeyPressed(const QString &key) { if (key == "space") { ClipCallback(); emit SignalClippedFinish(); } else if (key == "Escape") { if (widget_type_ == BOX) { clip_box_widget_->Off(); } else if (widget_type_ == SPHERE) { clip_sphere_widget_->Off(); } else if (widget_type_ == SPHERE) { seed_widget_->Off(); } emit SignalClippedFinish(); } } /** * @brief SurfaceClipper::SetEnable * 设置是否启动 * @param value */ void SurfaceClipper::SetEnable(const bool value) { if (widget_type_ == BOX) { clip_box_widget_->SetEnabled(value); } else if (widget_type_ == SPHERE) { clip_sphere_widget_->SetEnabled(value); } } /** * @brief SurfaceClipper::SlotSeedChanged * 点选取后槽函数 * @param caller * @param vtk_event * @param client_data * @param call_data */ void SurfaceClipper::SlotSeedChanged( vtkObject *caller, unsigned long vtk_event, void *client_data, void *call_data) { Q_UNUSED(client_data) if (vtk_event == vtkCommand::PlacePointEvent) { qint32 n = *static_cast<int *>(call_data); vtkSmartPointer<vtkSeedWidget> widget = dynamic_cast<vtkSeedWidget *>(caller); if (n >= 0 && widget) { qint32 num_seeds = widget->GetSeedRepresentation()->GetNumberOfSeeds(); if (num_seeds > 2) { this->seed_widget_->DeleteSeed(0); } } } }影像剪裁一般在平面选择切割方向让后利用vtkExtractVOI重新切割影像，网友问vtkExtractVOI + vtkBoxWidget应该是在空间剪裁。方法跟上边模型切割一样，周末不上边了补上。
Study-VTK：三维影像实现任意方向、大小的切割
