第一部分 VTK程序一般流程.ppt

报告人 邹水中日期 2010 4 2 VTK使用总结 内容简介 一 VTK程序一般流程二 VTK的数据对象接口三 VTK的面绘制 体绘制 多平面显示四 视点变换与相机控制五 VTK事件交互 VTK与MFC混合编程六 VTK视窗控制与文本标注七 VTK在测量中应用与VTK数据切割 第一部分VTK程序一般流程 VisualizationToolkit的机制VisualizationToolkit是一个用于可视化应用程序构造与运行的支撑环境 它是在三维函数库OpenGL的基础上采用面向对象的设计方法发展起来的 它将在可视化开发过程中会经常遇到的细节屏蔽起来 并将一些常用的算法封装起来 比如VisualizationToolkit将在表面重建中比较常见的MarchingCubes算法封装起来 以类的形式给以支持 这样在对三维规则点阵数据进行表面重建时就不必再重复编写MarchingCubes算法的代码而直接使用VisualizationToolkit中已经提供的vtkMarchingCubes类 VisualizationToolkit的框架结构 图形流水线 将几何数据转换为图像 可视化流水线 将信息转换为几何数据 另一种看法是 可视化流水线 负责构建几何表示 图形流水线 负责绘制 vtk使用一种lazy评价机制 对于lazy评价机制 通常无需人工地调用Update 因为filters连接着可视化流水线 当actor接收到绘制本身的要求会将方法回馈到他的mapper 然后Update方法自动发送至可视化流水线 Render方法通常开始数据要求 数据被通过流水线向下投递 依赖于流水线的哪个端口过时 流水线中的filters可能重新执行 将数据送至更新的流水线末端 通过actor绘制 可视化模型 VTK图形模型由以下核心对象组成vtkActor vtkActor2D vtkVolume vtkProp和 或vtpProp3D的子类vtkLightvtkCameravtkProperty vtkProperty2DvtkMaper vtkMapper2D vtkAbstractMapper的子类vtkTransformvtkLookupTable vtkColorTransferFunction vtkScalarsToColors的子类 forobjectsthatconvertscalarstocolorsvtkRendervtkRenderWindowvtkRenderWindowInteractor 图形模型 vtkLight用来展示和操控场景中的灯光 只在3D中用到 VtkCamera控制3D几何投影到2D 定位 定点 方向 还控制视角投影和立体视图 vtkMapper与查找表vtkLookupTable联合使用 用于转换和绘制几何体 Mapper提供可视化流水线和图形模型 vtkLookupTable是vtkScalarsToColors和vtkColorTransferFunction的子类 vtkRenderer和vtkRenderWindow用来管理图形机与电脑窗口系统的接口 可以生成多个renderwindows 每个renderwindows中有多个renderer去绘制 一个renderwindow中可以有多个区域 视窗 vtkRenderWindowInteractor用于与场景交互 操纵camera 选择对象 vtkWin32OpenGLRenderWindow和vtkWin32RenderWindowInteractorvtkWin32OpenGLRenderWindowisaconcreteimplementationoftheabstractclassvtkRenderWindow vtkWin32OpenGLRendererinterfacestothestandardOpenGLgraphicslibraryintheWindows NTenvironment implementsWin32specificfunctionsrequiredbyvtkRenderWindowInteractor vtkActor的子类vtkAssembly vtkFollower vtkLODActor等 vtkAssembly允许actors分层 在层级平移 旋转 缩放时合理转换 vtkLODActor在改变几何表示时保持交互帧速率 示例代码1演示VTK一般流程及常用类的使用 vtkVolume16Reader v16 vtkVolume16Reader New v16 SetDataDimensions 64 64 v16 SetDataByteOrderToLittleEndian v16 SetFilePrefix D VTK5 4 VTKData Data headsq quarter v16 SetImageRange 1 93 v16 SetDataSpacing 3 2 3 2 1 5 vtkContourFilter skinExtractor vtkContourFilter New skinExtractor SetInputConnection v16 GetOutputPort skinExtractor SetValue 0 500 vtkPolyDataNormals skinNormals vtkPolyDataNormals New skinNormals SetInputConnection skinExtractor GetOutputPort skinNormals SetFeatureAngle 60 0 ifthesurfacenormalbetweentwoadjacenttrianglesis FeatureAngle anedgeexistsvtkStripper skinStripper vtkStripper New skinStripper SetInputConnection skinNormals GetOutputPort vtkPolyDataMapper skinMapper vtkPolyDataMapper New skinMapper SetInputConnection skinStripper GetOutputPort skinMapper ScalarVisibilityOff 示例代码1 vtkActor skin vtkActor New skin SetMapper skinMapper skin GetProperty SetDiffuseColor 1 49 25 skin GetProperty SetSpecular 3 skin GetProperty SetSpecularPower 20 vtkLookupTable bwLut vtkLookupTable New bwLut SetTableRange 0 2000 bwLut SetSaturationRange 0 1 bwLut SetHueRange 0 1 bwLut SetValueRange 0 5 1 bwLut Build effectivebuilt TheresultisanimageoftypeVTK UNSIGNED CHARvtkImageMapToColors saggitalColors vtkImageMapToColors New saggitalColors SetInputConnection v16 GetOutputPort saggitalColors SetLookupTable bwLut vtkImageActor saggital vtkImageActor New saggital SetInput saggitalColors GetOutput saggital SetDisplayExtent 32 32 0 63 0 92 vtkRenderer aRenderer vtkRenderer New vtkRenderWindow renWin vtkRenderWindow New renWin AddRenderer aRenderer vtkRenderWindowInteractor iren vtkRenderWindowInteractor New iren SetRenderWindow renWin vtkCamera aCamera vtkCamera New aCamera SetViewUp 0 0 1 aCamera SetPosition 0 1 0 aCamera SetFocalPoint 0 0 0 aCamera ComputeViewPlaneNormal aRenderer AddActor saggital skin GetProperty SetOpacity 0 5 aRenderer SetActiveCamera aCamera aRenderer Render aRenderer ResetCamera aCamera Dolly 1 5 aRenderer SetBackground 1 1 1 aRenderer ResetCameraClippingRange renWin SetSize 640 480 iren Initialize iren Start 示例代码3演示视窗显示控制 相机控制 classvtkWidgetWindowLevelCallback publicvtkCommand public staticvtkWidgetWindowLevelCallback New returnnewvtkWidgetWindowLevelCallback voidExecute vtkObject caller unsignedlongvtkNotUsed event void callData vtkImagePlaneWidget self reinterpret cast caller if self return double wl static cast callData if self this WidgetX this WidgetY SetWindowLevel wl 0 wl 1 this WidgetZ SetWindowLevel wl 0 wl 1 elseif self this WidgetY this WidgetX SetWindowLevel wl 0 wl 1 this WidgetZ SetWindowLevel wl 0 wl 1 elseif self this WidgetZ this WidgetX SetWindowLevel wl 0 wl 1 this WidgetY SetWindowLevel wl 0 wl 1 vtkWidgetWindowLevelCallback WidgetX 0 WidgetY 0 WidgetZ 0 vtkImagePlaneWidget WidgetX vtkImagePlaneWidget WidgetY vtkImagePlaneWidget WidgetZ intmain intargc char argv vtkRenderer ren1 vtkRenderer New vtkRenderer ren2 vtkRenderer New vtkRenderer ren3 vtkRenderer New vtkRenderer ren vtkRenderer New vtkRenderWindow renWin vtkRenderWindow New vtkRenderWindowInteractor iren vtkRenderWindowInteractor New iren SetRenderWindow renWin renWin AddRenderer ren1 renWin AddRenderer ren2 renWin AddRenderer ren3 renWin AddRenderer ren vtkDICOMImageReader v16 vtkDICOMImageReader New v16 SetDataByteOrderToLittleEndian v16 SetDirectoryName E MedImageData 336 v16 Update vtkOutlineFilter outline vtkOutlineFilter New outline SetInputConnection v16 GetOutputPort vtkPolyDataMapper outlineMapper vtkPolyDataMapper New outlineMapper SetInputConnection outline GetOutputPort vtkActor outlineActor vtkActor New outlineActor SetMapper outlineMapper vtkWidgetWindowLevelCallback cbk vtkWidgetWindowLevelCallback New cbk WidgetX planeWidgetX cbk WidgetY planeWidgetY cbk WidgetZ planeWidgetZ planeWidgetX AddObserver vtkCommand EndWindowLevelEvent cbk planeWidgetY AddObserver vtkCommand EndWindowLevelEvent cbk planeWidgetZ AddObserver vtkCommand EndWindowLevelEvent cbk cbk Delete vtkImageMapToColors colorMap1 vtkImageMapToColors New colorMap1 PassAlphaToOutputOff colorMap1 SetActiveComponent 0 colorMap1 SetOutputFormatToLuminance colorMap1 SetInput planeWidgetX GetResliceOutput colorMap1 SetLookupTable planeWidgetX GetLookupTable vtkImageActor imageActor1 vtkImageActor New imageActor1 PickableOff imageActor1 SetInput colorMap1 GetOutput ren AddActor outlineActor ren1 AddActor imageActor1 ren2 AddActor imageActor2 ren3 AddActor imageActor3 ren SetBackground 0 1 0 1 0 2 ren1 SetBackground 0 1 0 2 0 1 ren2 SetBackground 0 2 0 1 0 2 ren3 SetBackground 0 2 0 2 0 2 renWin SetSize 600 400 ren SetViewport 0 0 5 0 5 1 ren1 SetViewport 0 5 0 5 1 1 ren2 SetViewport 0 0 0 5 0 5 ren3 SetViewport 0 5 0 1 0 5 renWin Render ren GetActiveCamera Elevation 110 ren GetActiveCamera SetViewUp 0 0 1 ren GetActiveCamera Azimuth 45 ren GetActiveCamera Dolly 1 15 ren ResetCameraClippingRange iren Initialize iren Start renWin Render iren SetKeyCode z iren InvokeEvent vtkCommand CharEvent NULL iren SetKeyCode z iren InvokeEvent vtkCommand CharEven