58网站怎么做浏览度才高,jsp借书网站开发,深圳航空公司航班动态,安卓系统软件开发培训VTK (Visualization Toolkit) 是一个强大的开源可视化库#xff0c;非常适合处理点云数据。下面将介绍如何使用 VTK 显示大量点云数据#xff0c;并实现点云拾取、着色、测量等功能。
基本点云显示
创建一个基本的点云显示程序#xff1a;
cpp
#include vtkSmartPoi… VTK (Visualization Toolkit) 是一个强大的开源可视化库非常适合处理点云数据。下面将介绍如何使用 VTK 显示大量点云数据并实现点云拾取、着色、测量等功能。
基本点云显示
创建一个基本的点云显示程序
cpp
#include vtkSmartPointer.h
#include vtkPoints.h
#include vtkPolyData.h
#include vtkPolyDataMapper.h
#include vtkActor.h
#include vtkRenderer.h
#include vtkRenderWindow.h
#include vtkRenderWindowInteractor.h
#include vtkVertexGlyphFilter.hint main() {// 创建点云数据vtkSmartPointervtkPoints points vtkSmartPointervtkPoints::New();// 添加大量点这里示例添加100万个随机点for (int i 0; i 1000000; i) {points-InsertNextPoint((double)rand() / RAND_MAX * 100.0,(double)rand() / RAND_MAX * 100.0,(double)rand() / RAND_MAX * 100.0);}// 创建PolyData对象并设置点vtkSmartPointervtkPolyData polydata vtkSmartPointervtkPolyData::New();polydata-SetPoints(points);// 使用VertexGlyphFilter将点转换为可渲染的顶点vtkSmartPointervtkVertexGlyphFilter glyphFilter vtkSmartPointervtkVertexGlyphFilter::New();glyphFilter-SetInputData(polydata);glyphFilter-Update();// 创建mapper和actorvtkSmartPointervtkPolyDataMapper mapper vtkSmartPointervtkPolyDataMapper::New();mapper-SetInputConnection(glyphFilter-GetOutputPort());vtkSmartPointervtkActor actor vtkSmartPointervtkActor::New();actor-SetMapper(mapper);actor-GetProperty()-SetPointSize(2); // 设置点大小// 创建渲染器、渲染窗口和交互器vtkSmartPointervtkRenderer renderer vtkSmartPointervtkRenderer::New();vtkSmartPointervtkRenderWindow renderWindow vtkSmartPointervtkRenderWindow::New();renderWindow-AddRenderer(renderer);vtkSmartPointervtkRenderWindowInteractor renderWindowInteractor vtkSmartPointervtkRenderWindowInteractor::New();renderWindowInteractor-SetRenderWindow(renderWindow);// 添加actor到渲染器renderer-AddActor(actor);renderer-SetBackground(0.1, 0.2, 0.4); // 设置背景颜色// 开始渲染renderWindow-Render();renderWindowInteractor-Start();return 0;
}
点云拾取功能
要实现点云拾取可以使用 VTK 的点拾取器 (vtkPointPicker):
cpp
#include vtkPointPicker.h// 在main函数中创建交互器后添加以下代码// 创建点拾取器
vtkSmartPointervtkPointPicker pointPicker vtkSmartPointervtkPointPicker::New();
renderWindowInteractor-SetPicker(pointPicker);// 添加观察者处理拾取事件
vtkSmartPointervtkCallbackCommand pickCallback vtkSmartPointervtkCallbackCommand::New();
pickCallback-SetCallback([](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {vtkRenderWindowInteractor* interactor static_castvtkRenderWindowInteractor*(caller);vtkPointPicker* picker static_castvtkPointPicker*(interactor-GetPicker());int x interactor-GetEventPosition()[0];int y interactor-GetEventPosition()[1];picker-Pick(x, y, 0, interactor-GetRenderWindow()-GetRenderers()-GetFirstRenderer());vtkIdType pointId picker-GetPointId();if (pointId ! -1) {double* pos picker-GetPickPosition();std::cout Picked point ID: pointId std::endl;std::cout Position: ( pos[0] , pos[1] , pos[2] ) std::endl;}
});renderWindowInteractor-AddObserver(vtkCommand::LeftButtonPressEvent, pickCallback);
点云着色功能
可以为点云添加颜色属性实现着色效果
cpp
#include vtkUnsignedCharArray.h// 在创建点数据后添加颜色数组
vtkSmartPointervtkUnsignedCharArray colors vtkSmartPointervtkUnsignedCharArray::New();
colors-SetNumberOfComponents(3); // RGB
colors-SetName(Colors);// 为每个点添加随机颜色
for (int i 0; i points-GetNumberOfPoints(); i) {unsigned char color[3] {static_castunsigned char(rand() % 256),static_castunsigned char(rand() % 256),static_castunsigned char(rand() % 256)};colors-InsertNextTypedTuple(color);
}polydata-GetPointData()-SetScalars(colors);// 然后修改mapper以使用这些颜色
mapper-SetScalarVisibility(1); // 启用标量颜色
mapper-SetScalarModeToUsePointData(); // 使用点数据中的标量
点云测量功能
1. 点对点距离测量
首先实现最基本的点对点距离测量功能
#include vtkDistanceWidget.h
#include vtkDistanceRepresentation3D.h
#include vtkSphereSource.h// 在main函数中创建交互器后添加以下代码// 创建距离测量工具
vtkSmartPointervtkDistanceWidget distanceWidget vtkSmartPointervtkDistanceWidget::New();
distanceWidget-SetInteractor(renderWindowInteractor);
distanceWidget-CreateDefaultRepresentation();// 设置距离表示的样式
vtkDistanceRepresentation3D* distanceRep vtkDistanceRepresentation3D::SafeDownCast(distanceWidget-GetRepresentation());
distanceRep-SetLabelFormat(%-#6.3g mm); // 设置显示格式
distanceRep-GetAxisProperty()-SetColor(1, 0, 0); // 设置轴线颜色
distanceRep-GetAxisProperty()-SetLineWidth(2); // 设置线宽// 添加标记球体
vtkSmartPointervtkSphereSource sphere1 vtkSmartPointervtkSphereSource::New();
sphere1-SetRadius(1.0);
vtkSmartPointervtkSphereSource sphere2 vtkSmartPointervtkSphereSource::New();
sphere2-SetRadius(1.0);distanceRep-SetPoint1Representation(sphere1-GetOutput());
distanceRep-SetPoint2Representation(sphere2-GetOutput());// 启用距离测量工具
distanceWidget-On();
2. 多点距离测量折线测量
如果需要测量多点间的累计距离可以实现折线测量
#include vtkContourWidget.h
#include vtkOrientedGlyphContourRepresentation.h
#include vtkPolygonalSurfacePointPlacer.h// 创建折线测量工具
vtkSmartPointervtkContourWidget contourWidget vtkSmartPointervtkContourWidget::New();
contourWidget-SetInteractor(renderWindowInteractor);
contourWidget-ContinuousDrawOn(); // 启用连续绘制// 设置表示方式
vtkOrientedGlyphContourRepresentation* contourRep vtkOrientedGlyphContourRepresentation::SafeDownCast(contourWidget-GetRepresentation());
contourRep-GetLinesProperty()-SetColor(0, 1, 0); // 设置线颜色
contourRep-GetLinesProperty()-SetLineWidth(2); // 设置线宽// 设置点放置器使点吸附到点云上
vtkSmartPointervtkPolygonalSurfacePointPlacer pointPlacer vtkSmartPointervtkPolygonalSurfacePointPlacer::New();
pointPlacer-AddProp(actor);
pointPlacer-GetPolys()-AddItem(polydata);
contourRep-SetPointPlacer(pointPlacer);// 添加回调函数计算总长度
vtkSmartPointervtkCallbackCommand contourCallback vtkSmartPointervtkCallbackCommand::New();
contourCallback-SetCallback([](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {vtkContourWidget* widget static_castvtkContourWidget*(caller);vtkContourRepresentation* rep widget-GetContourRepresentation();int numPoints rep-GetNumberOfNodes();if (numPoints 1) {double totalLength 0.0;double pos1[3], pos2[3];rep-GetNthNodeWorldPosition(0, pos1);for (int i 1; i numPoints; i) {rep-GetNthNodeWorldPosition(i, pos2);totalLength sqrt(vtkMath::Distance2BetweenPoints(pos1, pos2));memcpy(pos1, pos2, 3 * sizeof(double));}std::cout Total length: totalLength mm std::endl;}
});contourWidget-AddObserver(vtkCommand::InteractionEvent, contourCallback);
contourWidget-On();
3. 面积测量多边形区域
对于闭合区域的面积测量
#include vtkPolygon.h
#include vtkCellArray.h// 修改contourWidget的回调函数以支持面积计算
contourCallback-SetCallback([](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {vtkContourWidget* widget static_castvtkContourWidget*(caller);vtkContourRepresentation* rep widget-GetContourRepresentation();int numPoints rep-GetNumberOfNodes();if (numPoints 2) {// 计算周长double totalLength 0.0;double pos1[3], pos2[3];rep-GetNthNodeWorldPosition(0, pos1);for (int i 1; i numPoints; i) {rep-GetNthNodeWorldPosition(i, pos2);totalLength sqrt(vtkMath::Distance2BetweenPoints(pos1, pos2));memcpy(pos1, pos2, 3 * sizeof(double));}// 闭合路径rep-GetNthNodeWorldPosition(0, pos2);totalLength sqrt(vtkMath::Distance2BetweenPoints(pos1, pos2));// 计算面积vtkSmartPointervtkPoints points vtkSmartPointervtkPoints::New();for (int i 0; i numPoints; i) {rep-GetNthNodeWorldPosition(i, pos1);points-InsertNextPoint(pos1);}vtkSmartPointervtkPolygon polygon vtkSmartPointervtkPolygon::New();polygon-Initialize(numPoints, points-GetPoints(), points-GetBounds());double area polygon-ComputeArea();std::cout Perimeter: totalLength mm std::endl;std::cout Area: area mm² std::endl;}
});
4. 点云高度差测量
对于三维点云可以测量高度差
// 在点拾取回调中添加高度差计算
pickCallback-SetCallback([](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {static double lastPos[3] {0, 0, 0};static bool firstPick true;vtkRenderWindowInteractor* interactor static_castvtkRenderWindowInteractor*(caller);vtkPointPicker* picker static_castvtkPointPicker*(interactor-GetPicker());int x interactor-GetEventPosition()[0];int y interactor-GetEventPosition()[1];picker-Pick(x, y, 0, interactor-GetRenderWindow()-GetRenderers()-GetFirstRenderer());vtkIdType pointId picker-GetPointId();if (pointId ! -1) {double* pos picker-GetPickPosition();std::cout Picked point ID: pointId std::endl;std::cout Position: ( pos[0] , pos[1] , pos[2] ) std::endl;if (!firstPick) {double distance sqrt(vtkMath::Distance2BetweenPoints(pos, lastPos));double heightDiff fabs(pos[2] - lastPos[2]);std::cout Distance from last point: distance mm std::endl;std::cout Height difference: heightDiff mm std::endl;}memcpy(lastPos, pos, 3 * sizeof(double));firstPick false;}
});
5. 测量结果显示在3D视图
将测量结果直接显示在3D视图上
#include vtkTextActor.h
#include vtkTextProperty.h// 创建文本actor用于显示测量结果
vtkSmartPointervtkTextActor textActor vtkSmartPointervtkTextActor::New();
textActor-SetPosition(10, 10);
textActor-GetTextProperty()-SetFontSize(18);
textActor-GetTextProperty()-SetColor(1.0, 1.0, 1.0);
renderer-AddActor2D(textActor);// 修改距离测量的回调函数
distanceWidget-AddObserver(vtkCommand::InteractionEvent, [textActor](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {vtkDistanceWidget* widget static_castvtkDistanceWidget*(caller);vtkDistanceRepresentation3D* rep vtkDistanceRepresentation3D::SafeDownCast(widget-GetRepresentation());double distance rep-GetDistance();std::stringstream ss;ss Distance: std::fixed std::setprecision(2) distance mm;textActor-SetInput(ss.str().c_str());
});
6. 测量工具切换
添加键盘控制来切换不同的测量工具
// 添加键盘回调
vtkSmartPointervtkCallbackCommand keyCallback vtkSmartPointervtkCallbackCommand::New();
keyCallback-SetCallback([](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {vtkRenderWindowInteractor* interactor static_castvtkRenderWindowInteractor*(caller);std::string key interactor-GetKeySym();static vtkDistanceWidget* distanceWidget static_castvtkDistanceWidget*(clientData);static vtkContourWidget* contourWidget static_castvtkContourWidget*(clientData);if (key d) {// 切换距离测量distanceWidget-SetEnabled(!distanceWidget-GetEnabled());contourWidget-SetEnabled(false);} else if (key c) {// 切换轮廓测量contourWidget-SetEnabled(!contourWidget-GetEnabled());distanceWidget-SetEnabled(false);} else if (key a) {// 切换面积测量bool enabled contourWidget-GetEnabled();contourWidget-SetEnabled(!enabled);distanceWidget-SetEnabled(false);if (enabled) {contourWidget-CloseLoop();}}
});renderWindowInteractor-AddObserver(vtkCommand::KeyPressEvent, keyCallback);
性能优化
对于大量点云数据可以考虑以下优化措施
1、使用vtkOctreePointLocator 加速点查找
#include vtkOctreePointLocator.hvtkSmartPointervtkOctreePointLocator pointLocator vtkSmartPointervtkOctreePointLocator::New();
pointLocator-SetDataSet(polydata);
pointLocator-BuildLocator();// 拾取时使用locator查找最近点
double searchPoint[3] {x, y, z};
vtkIdType pointId pointLocator-FindClosestPoint(searchPoint);
2、使用点云简化 减少显示点数
#include vtkQuadricClustering.hvtkSmartPointervtkQuadricClustering decimate vtkSmartPointervtkQuadricClustering::New();
decimate-SetInputData(polydata);
decimate-SetNumberOfDivisions(50, 50, 50); // 调整简化程度
decimate-Update();
3、使用GPU加速
#include vtkGPUInfo.h
#include vtkGPUInfoList.h// 检查GPU信息
vtkSmartPointervtkGPUInfoList infoList vtkSmartPointervtkGPUInfoList::New();
infoList-Probe();if (infoList-GetNumberOfGPUs() 0) {mapper-SetUseHardwareShading(true);
}
完整示例
完整示例1点云显示点云拾取点云着色
#include vtkSmartPointer.h
#include vtkPoints.h
#include vtkPolyData.h
#include vtkPolyDataMapper.h
#include vtkActor.h
#include vtkRenderer.h
#include vtkRenderWindow.h
#include vtkRenderWindowInteractor.h
#include vtkVertexGlyphFilter.h
#include vtkUnsignedCharArray.h
#include vtkPointPicker.h
#include vtkCallbackCommand.h
#include vtkOctreePointLocator.h
#include iostreamint main() {// 创建点云数据vtkSmartPointervtkPoints points vtkSmartPointervtkPoints::New();// 添加10万个随机点for (int i 0; i 100000; i) {points-InsertNextPoint((double)rand() / RAND_MAX * 100.0,(double)rand() / RAND_MAX * 100.0,(double)rand() / RAND_MAX * 100.0);}// 创建颜色数组vtkSmartPointervtkUnsignedCharArray colors vtkSmartPointervtkUnsignedCharArray::New();colors-SetNumberOfComponents(3);colors-SetName(Colors);for (int i 0; i points-GetNumberOfPoints(); i) {unsigned char color[3] {static_castunsigned char(rand() % 256),static_castunsigned char(rand() % 256),static_castunsigned char(rand() % 256)};colors-InsertNextTypedTuple(color);}// 创建PolyData对象vtkSmartPointervtkPolyData polydata vtkSmartPointervtkPolyData::New();polydata-SetPoints(points);polydata-GetPointData()-SetScalars(colors);// 创建点定位器用于加速拾取vtkSmartPointervtkOctreePointLocator pointLocator vtkSmartPointervtkOctreePointLocator::New();pointLocator-SetDataSet(polydata);pointLocator-BuildLocator();// 将点转换为可渲染的顶点vtkSmartPointervtkVertexGlyphFilter glyphFilter vtkSmartPointervtkVertexGlyphFilter::New();glyphFilter-SetInputData(polydata);glyphFilter-Update();// 创建mapper和actorvtkSmartPointervtkPolyDataMapper mapper vtkSmartPointervtkPolyDataMapper::New();mapper-SetInputConnection(glyphFilter-GetOutputPort());mapper-SetScalarVisibility(1);mapper-SetScalarModeToUsePointData();vtkSmartPointervtkActor actor vtkSmartPointervtkActor::New();actor-SetMapper(mapper);actor-GetProperty()-SetPointSize(3);// 创建渲染器和窗口vtkSmartPointervtkRenderer renderer vtkSmartPointervtkRenderer::New();vtkSmartPointervtkRenderWindow renderWindow vtkSmartPointervtkRenderWindow::New();renderWindow-AddRenderer(renderer);renderWindow-SetSize(800, 600);vtkSmartPointervtkRenderWindowInteractor renderWindowInteractor vtkSmartPointervtkRenderWindowInteractor::New();renderWindowInteractor-SetRenderWindow(renderWindow);// 设置点拾取器vtkSmartPointervtkPointPicker pointPicker vtkSmartPointervtkPointPicker::New();renderWindowInteractor-SetPicker(pointPicker);// 添加拾取回调vtkSmartPointervtkCallbackCommand pickCallback vtkSmartPointervtkCallbackCommand::New();pickCallback-SetCallback([](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {vtkRenderWindowInteractor* interactor static_castvtkRenderWindowInteractor*(caller);int x interactor-GetEventPosition()[0];int y interactor-GetEventPosition()[1];interactor-GetPicker()-Pick(x, y, 0, interactor-GetRenderWindow()-GetRenderers()-GetFirstRenderer());vtkPointPicker* picker static_castvtkPointPicker*(interactor-GetPicker());vtkIdType pointId picker-GetPointId();if (pointId ! -1) {double* pos picker-GetPickPosition();std::cout Picked point ID: pointId std::endl;std::cout Position: ( pos[0] , pos[1] , pos[2] ) std::endl;// 高亮显示选中的点例如改变颜色// 这里可以添加代码修改选中点的颜色}});renderWindowInteractor-AddObserver(vtkCommand::LeftButtonPressEvent, pickCallback);// 添加actor到渲染器renderer-AddActor(actor);renderer-SetBackground(0.1, 0.2, 0.4);// 开始渲染renderWindow-Render();renderWindowInteractor-Start();return 0;
}
完整示例2点云测量
#include vtkSmartPointer.h
#include vtkPoints.h
#include vtkPolyData.h
#include vtkPolyDataMapper.h
#include vtkActor.h
#include vtkRenderer.h
#include vtkRenderWindow.h
#include vtkRenderWindowInteractor.h
#include vtkVertexGlyphFilter.h
#include vtkUnsignedCharArray.h
#include vtkPointPicker.h
#include vtkCallbackCommand.h
#include vtkDistanceWidget.h
#include vtkDistanceRepresentation3D.h
#include vtkSphereSource.h
#include vtkContourWidget.h
#include vtkOrientedGlyphContourRepresentation.h
#include vtkPolygonalSurfacePointPlacer.h
#include vtkTextActor.h
#include vtkTextProperty.h
#include vtkMath.h
#include iostream
#include sstream
#include iomanipint main() {// 创建点云数据vtkSmartPointervtkPoints points vtkSmartPointervtkPoints::New();// 添加随机点for (int i 0; i 50000; i) {points-InsertNextPoint((double)rand() / RAND_MAX * 100.0,(double)rand() / RAND_MAX * 100.0,(double)rand() / RAND_MAX * 20.0); // Z轴范围小一些便于观察高度差}// 创建颜色数组vtkSmartPointervtkUnsignedCharArray colors vtkSmartPointervtkUnsignedCharArray::New();colors-SetNumberOfComponents(3);colors-SetName(Colors);for (int i 0; i points-GetNumberOfPoints(); i) {unsigned char color[3] {static_castunsigned char(rand() % 256),static_castunsigned char(rand() % 256),static_castunsigned char(rand() % 256)};colors-InsertNextTypedTuple(color);}// 创建PolyData对象vtkSmartPointervtkPolyData polydata vtkSmartPointervtkPolyData::New();polydata-SetPoints(points);polydata-GetPointData()-SetScalars(colors);// 将点转换为可渲染的顶点vtkSmartPointervtkVertexGlyphFilter glyphFilter vtkSmartPointervtkVertexGlyphFilter::New();glyphFilter-SetInputData(polydata);glyphFilter-Update();// 创建mapper和actorvtkSmartPointervtkPolyDataMapper mapper vtkSmartPointervtkPolyDataMapper::New();mapper-SetInputConnection(glyphFilter-GetOutputPort());mapper-SetScalarVisibility(1);mapper-SetScalarModeToUsePointData();vtkSmartPointervtkActor actor vtkSmartPointervtkActor::New();actor-SetMapper(mapper);actor-GetProperty()-SetPointSize(3);// 创建渲染器和窗口vtkSmartPointervtkRenderer renderer vtkSmartPointervtkRenderer::New();vtkSmartPointervtkRenderWindow renderWindow vtkSmartPointervtkRenderWindow::New();renderWindow-AddRenderer(renderer);renderWindow-SetSize(800, 600);vtkSmartPointervtkRenderWindowInteractor renderWindowInteractor vtkSmartPointervtkRenderWindowInteractor::New();renderWindowInteractor-SetRenderWindow(renderWindow);// 设置点拾取器vtkSmartPointervtkPointPicker pointPicker vtkSmartPointervtkPointPicker::New();renderWindowInteractor-SetPicker(pointPicker);// 创建文本actor用于显示测量结果vtkSmartPointervtkTextActor textActor vtkSmartPointervtkTextActor::New();textActor-SetPosition(10, 10);textActor-GetTextProperty()-SetFontSize(18);textActor-GetTextProperty()-SetColor(1.0, 1.0, 1.0);renderer-AddActor2D(textActor);// 创建距离测量工具vtkSmartPointervtkDistanceWidget distanceWidget vtkSmartPointervtkDistanceWidget::New();distanceWidget-SetInteractor(renderWindowInteractor);distanceWidget-CreateDefaultRepresentation();vtkDistanceRepresentation3D* distanceRep vtkDistanceRepresentation3D::SafeDownCast(distanceWidget-GetRepresentation());distanceRep-SetLabelFormat(%-#6.3g mm);distanceRep-GetAxisProperty()-SetColor(1, 0, 0);distanceRep-GetAxisProperty()-SetLineWidth(2);vtkSmartPointervtkSphereSource sphere1 vtkSmartPointervtkSphereSource::New();sphere1-SetRadius(1.0);vtkSmartPointervtkSphereSource sphere2 vtkSmartPointervtkSphereSource::New();sphere2-SetRadius(1.0);distanceRep-SetPoint1Representation(sphere1-GetOutput());distanceRep-SetPoint2Representation(sphere2-GetOutput());distanceWidget-AddObserver(vtkCommand::InteractionEvent, [textActor](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {vtkDistanceWidget* widget static_castvtkDistanceWidget*(caller);vtkDistanceRepresentation3D* rep vtkDistanceRepresentation3D::SafeDownCast(widget-GetRepresentation());double distance rep-GetDistance();std::stringstream ss;ss Distance: std::fixed std::setprecision(2) distance mm;textActor-SetInput(ss.str().c_str());});// 创建轮廓测量工具vtkSmartPointervtkContourWidget contourWidget vtkSmartPointervtkContourWidget::New();contourWidget-SetInteractor(renderWindowInteractor);contourWidget-ContinuousDrawOn();vtkOrientedGlyphContourRepresentation* contourRep vtkOrientedGlyphContourRepresentation::SafeDownCast(contourWidget-GetRepresentation());contourRep-GetLinesProperty()-SetColor(0, 1, 0);contourRep-GetLinesProperty()-SetLineWidth(2);vtkSmartPointervtkPolygonalSurfacePointPlacer pointPlacer vtkSmartPointervtkPolygonalSurfacePointPlacer::New();pointPlacer-AddProp(actor);pointPlacer-GetPolys()-AddItem(polydata);contourRep-SetPointPlacer(pointPlacer);contourWidget-AddObserver(vtkCommand::InteractionEvent, [textActor](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {vtkContourWidget* widget static_castvtkContourWidget*(caller);vtkContourRepresentation* rep widget-GetContourRepresentation();int numPoints rep-GetNumberOfNodes();if (numPoints 1) {// 计算周长double totalLength 0.0;double pos1[3], pos2[3];rep-GetNthNodeWorldPosition(0, pos1);for (int i 1; i numPoints; i) {rep-GetNthNodeWorldPosition(i, pos2);totalLength sqrt(vtkMath::Distance2BetweenPoints(pos1, pos2));memcpy(pos1, pos2, 3 * sizeof(double));}std::stringstream ss;ss Perimeter: std::fixed std::setprecision(2) totalLength mm;// 如果闭合计算面积if (numPoints 2 rep-IsClosed()) {vtkSmartPointervtkPoints points vtkSmartPointervtkPoints::New();for (int i 0; i numPoints; i) {rep-GetNthNodeWorldPosition(i, pos1);points-InsertNextPoint(pos1);}vtkSmartPointervtkPolygon polygon vtkSmartPointervtkPolygon::New();polygon-Initialize(numPoints, points-GetPoints(), points-GetBounds());double area polygon-ComputeArea();ss \nArea: std::fixed std::setprecision(2) area mm²;}textActor-SetInput(ss.str().c_str());}});// 添加键盘控制vtkSmartPointervtkCallbackCommand keyCallback vtkSmartPointervtkCallbackCommand::New();keyCallback-SetCallback([distanceWidget, contourWidget, textActor](vtkObject* caller, unsigned long eventId, void* clientData, void* callData) {vtkRenderWindowInteractor* interactor static_castvtkRenderWindowInteractor*(caller);std::string key interactor-GetKeySym();if (key d || key D) {// 切换距离测量distanceWidget-SetEnabled(!distanceWidget-GetEnabled());contourWidget-SetEnabled(false);textActor-SetInput(Distance measurement mode (click two points));} else if (key c || key C) {// 切换轮廓测量contourWidget-SetEnabled(!contourWidget-GetEnabled());distanceWidget-SetEnabled(false);textActor-SetInput(Contour measurement mode (click multiple points));} else if (key a || key A) {// 切换面积测量bool enabled !contourWidget-GetEnabled();contourWidget-SetEnabled(enabled);distanceWidget-SetEnabled(false);if (enabled) {textActor-SetInput(Area measurement mode (click points to close loop));contourWidget-CloseLoop();}} else if (key Escape) {// 退出所有测量模式distanceWidget-SetEnabled(false);contourWidget-SetEnabled(false);textActor-SetInput();}});renderWindowInteractor-AddObserver(vtkCommand::KeyPressEvent, keyCallback);// 添加actor到渲染器renderer-AddActor(actor);renderer-SetBackground(0.1, 0.2, 0.4);// 开始渲染renderWindow-Render();// 显示操作提示std::cout Measurement Controls: std::endl;std::cout D - Toggle distance measurement std::endl;std::cout C - Toggle contour measurement std::endl;std::cout A - Toggle area measurement std::endl;std::cout ESC - Exit measurement mode std::endl;renderWindowInteractor-Start();return 0;
}
功能说明 距离测量按 D 键激活点击两个点测量它们之间的距离 轮廓测量按 C 键激活点击多个点测量折线总长度 面积测量按 A 键激活点击多个点后闭合区域测量面积 结果显示测量结果实时显示在3D视图左上角 退出测量按 ESC 键退出所有测量模式
