vtk绘制直线示例
引言
初学vtk，很多都不懂，于是开始探索之路。这篇主要是vtk绘制直线的示例。
本文通过集中不同的方式，来创建三位空间中的直线，由单一的直线到多条直线。
开发环境
本人使用的是QtCreator开发的vtk相关的程序。
QtCreator的版本：
vtk库的版本：vtk9.2
示例一（单根直线）
不同的vtk版本可能代码中会相差一些，本文只适用上述指定的开发环境下的编码运行。
创建项目
这里创建的是其它项目-》Empty qmake Project项目，即空项目。
完善项目
创建完空项目之后，编写pro文件，其pro文件中的内容如下：
QT += core #引入qt的核心模块，以防需要使用
CONFIG += c++11 vtk9.2 #使用C++11和vtk9.2的库
# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS
# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0
SOURCES += \
mian.cpp
#配置vtk的环境
SOUPDIR = $$PWD/../../SOUPdependency
vtk9.2 {
contains(QT_ARCH, x86_64) {
include($$SOUPDIR/vtk-9.2/vtk-9.2.pri)
} else {
include($$SOUPDIR/vtk-9.2-2017-omp-win32/vtk-9.2.pri)
}
DEFINES += vtkEventDataButton3D=vtkEventDataDevice3D
DEFINES += vtkEventDataMove3D=vtkEventDataDevice3D
}
# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target
环境配置略有不同，因为这里引入了pri文件，vtk的环境配置，需要自己自行配置。这里不提供。
编写完pro文件之后，添加新文件main.cpp。
main.cpp的代码：
#include 项目结构
运行结果
示例二（单根直线）
示例二也是在QtCreator下创建的空项目，其创建的项目的方式上面也有提到，这里不做讲解。创建好空项目之后，需要编写pro文件，同时也需要添加新文件main.cpp，下面直接上代码。
示例代码
pro文件内容
QT += core
#greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
CONFIG += c++11 vtk9.2
# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS
# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0
SOURCES += \
main.cpp
SOUPDIR = $$PWD/../../SOUPdependency
vtk9.2 {
contains(QT_ARCH, x86_64) {
include($$SOUPDIR/vtk-9.2/vtk-9.2.pri)
} else {
include($$SOUPDIR/vtk-9.2-2017-omp-win32/vtk-9.2.pri)
}
DEFINES += vtkEventDataButton3D=vtkEventDataDevice3D
DEFINES += vtkEventDataMove3D=vtkEventDataDevice3D
}
# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target
main.cpp
#include 运行效果
示例三（单根直线）
该示例中采用vtkLine创建直线。pro文件中的内容与上面pro文件中的内容相同。下面直接上代码：
main.cpp
#include polyData = createPolyDataByPointArray();
// vtkSmartPointer polyData = createPolyDataByVtkLineSource();
vtkSmartPointer<vtkPolyData> polyData = createPolyDataByVtkLine();
vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputData(polyData);
vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
actor->GetProperty()->SetColor(0.94,0.502,0.502);
vtkSmartPointer<vtkRenderer> render = vtkSmartPointer<vtkRenderer>::New();
render->AddActor(actor);
render->SetBackground(0,0,0);
render->ResetCamera();
vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer(render);
renderWindow->SetSize(400,350);
renderWindow->Render();
vtkSmartPointer<vtkRenderWindowInteractor> interactor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
interactor->SetRenderWindow(renderWindow);
interactor->Initialize();
interactor->Start();
return 0;
}
运行结果同上面的运行结果一样。
总结
本文中创建单根直线，提供了三种创建直线的方式，vtkLineSource,vtkLine,vtkPolyData。
其中vtkLineSource通过两个点创建直线，最后获取polyData添加到mapper中。vtkLine与vtkPolyLine的区别是vtkLine创建单个直线，而vtkPolyLine可以创建多个直线。