vtk中截取图像显示

目录

• 1.CmakeLists
• 2.C++实现部分

部分项目中需要截取vtk图像进行显示

1.CmakeLists

#1.设置cmake的最小版本
cmake_minimum_required(VERSION 3.3...3.12 FATAL_ERROR)

#2.设置项目名称
project (Step2)
#3.查找vtk
find_package(VTK REQUIRED)
#4.vtk模块的设置
vtk_module_config(VTK
  vtkCommonCore
  vtkFiltersSources
  vtkFiltersSources
  vtkInteractionStyle
  vtkRenderingOpenGL2
  vtkIOImage
)

#5.包含头文件
include(${VTK_USE_FILE})
#6.添加可执行文件
add_executable(CubeAxesActor MACOSX_BUNDLE CubeAxesActor.cxx)
#7.为可执行文件链接库
target_link_libraries(CubeAxesActor ${VTK_LIBRARIES})

2.C++实现部分

#include "vtkActor.h"
#include "vtkCamera.h"
#include "vtkConeSource.h"
#include "vtkCellArray.h"
#include "vtkFloatArray.h"
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkPolyData.h"
#include "vtkPolyDataMapper.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkRenderer.h"
#include <vtkLookupTable.h>
#include <vtkWindowToImageFilter.h>
#include <vtkPNGWriter.h>
int main()
{
	int i;
	// 梯形的顶点坐标
	static float x[8][3] = {{0, 0, 0}, {4, 0, 0}, {4, 4, 0}, {0, 4, 0}, {1, 1, 1}, {3, 1, 1}, {3, 3, 1}, {1, 3, 1}};
	// 4个顶点构成一个单元，一共6个单元
	static vtkIdType y[6][4] = {{0, 1, 2, 3}, {4, 5, 6, 7}, {0, 1, 5, 4}, {1, 2, 6, 5}, {2, 3, 7, 6}, {3, 0, 4, 7}};

	vtkPoints *points = vtkPoints::New();
	for (i = 0; i < 8; i++)
		points->InsertPoint(i, x[i]);

	vtkCellArray *polys = vtkCellArray::New();
	for (i = 0; i < 6; i++)
		polys->InsertNextCell(4, y[i]);
	// 存储标量值
	vtkFloatArray *scalars = vtkFloatArray::New();
	for (i = 0; i < 8; i++)
		scalars->InsertTuple1(i, i);
	// 构建多边形数据
	vtkPolyData *cube = vtkPolyData::New();
	cube->SetPoints(points);
	// 设定单元的组成方式
	cube->SetPolys(polys);
	cube->GetPointData()->SetScalars(scalars);

	// 定义颜色映射表
	vtkLookupTable *pColorTable = vtkLookupTable::New();
	pColorTable->SetNumberOfColors(6);
	pColorTable->SetTableValue(0, 1.0, 0.0, 1.0, 1.0);
	pColorTable->SetTableValue(1, 0.0, 1.0, 1.0, 1.0);
	pColorTable->SetTableValue(2, 1.0, 1.0, 1.0, 1.0);
	pColorTable->SetTableValue(3, 1.0, 0.0, 1.0, 1.0);
	pColorTable->SetTableValue(4, 0.0, 0.0, 1.0, 1.0);
	pColorTable->SetTableValue(5, 1.0, 1.0, 0.0, 1.0);
	pColorTable->Build();

	/*数据映射*/
	vtkPolyDataMapper *cubeMapper = vtkPolyDataMapper::New();
	cubeMapper->SetInputData(cube);
	cubeMapper->SetScalarRange(0, 7);
	cubeMapper->SetLookupTable(pColorTable);

	vtkActor *cubeActor = vtkActor::New();//创建actor对象
	cubeActor->SetMapper(cubeMapper);
	
	vtkCamera *camera = vtkCamera::New();//vktcamera设置
	camera->SetPosition(1, 1, 1); //相机位置设置
	camera->SetFocalPoint(0, 0, 0);//相机焦点设置

	vtkRenderer *renderer = vtkRenderer::New();//创建vtkRenderer对象
	vtkRenderWindow *renWin = vtkRenderWindow::New();//创建vtkRenderer窗口对象
	renWin->AddRenderer(renderer);//将vtkRenderer与vtkRenderer窗口关联

	vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();//创建interactor对象
	iren->SetRenderWindow(renWin);//设置interactor的的renderwindow
	renderer->AddActor(cubeActor);//将actor加入到render中

	renderer->SetActiveCamera(camera);//renderer设置的的选择camera
	renderer->ResetCamera();//renderer相机重置
	renderer->SetBackground(1, 1, 1);//设置渲染的背景颜色

	renWin->SetSize(800, 800);//设置渲染窗口大小
	renWin->Render();


	/* vtkWindowToImageFilter屏幕截图*/
	vtkNew<vtkWindowToImageFilter> windowToImageFilter;//vtkWindowToImageFilter获取vtk窗体的图像
	windowToImageFilter->SetInput(renWin); // 设定输入窗口
	windowToImageFilter->SetInputBufferTypeToRGBA(); // 设置格式类型
#if VTK_MAJOR_VERSION >= 8 || VTK_MAJOR_VERSION == 8 && VTK_MINOR_VERSION >= 90
	windowToImageFilter->SetScale(1); 
#else
	windowToImageFilter->SetMagnification(2); 
#endif
	windowToImageFilter->SetInputBufferTypeToRGB(); // 设置图像存储图像格式
	windowToImageFilter->ReadFrontBufferOff();		
	windowToImageFilter->Update();


	/* vtkPNGWriter保存屏幕截取图像*/
	vtkNew<vtkPNGWriter> writer;
	writer->SetFileName("screenshot2.png");
	writer->SetInputConnection(windowToImageFilter->GetOutputPort());
	writer->Write();

	iren->Start();  //interactor如果开启无法截图

	// 删除
	points->Delete();
	polys->Delete();
	scalars->Delete();
	cube->Delete();
	cubeMapper->Delete();
	cubeActor->Delete();
	camera->Delete();
	renderer->Delete();
	renWin->Delete();
	iren->Delete();
	pColorTable->Delete();
	return 0;
}