VTK图形处理之颜色映射 ，vtkpolydata 数据合并_vtkcleanpolydata

颜色可以直接作为一种标量属性数据，设置到相应的点或者单元数据中，这是最直接的一种图形着色方式。

颜色映射

　　颜色映射的操作对象是数据集中的标量属性。它是一种常用的 标量算法。它会根据数据集中各个部分不同的标量值，对各个部分上不同的颜色。与此相关的另一种上色方法是控制演员的颜色属性，但这样整个图形只有单一的颜色，这显然没有颜色映射方法灵活。
　　创建多边形数据集程序运行 结果显示的彩色立方体就用到了颜色映射。由于对 立方体的6个顶点设置了不同的标量值（点id），所以这6个点的颜色不同。至于立方体其他部分的颜色，也是通过标量值映射来的，不过这些标量值并不是手动设置，而是根据邻近的顶点的标量值，运用某种内插算法计算出来的。

需求：

将两个数据合并，并两组vtkPoint 数据显示不同色；

#include <vtkSmartPointer.h>
#include <vtkPolyData.h>
#include <vtkFloatArray.h>
#include <vtkCellData.h>
#include <vtkLookupTable.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
 
int main(){
 
	vtkSmartPointer<vtkPoints> pts = vtkSmartPointer<vtkPoints>::New();
 
	pts->InsertNextPoint(0.0, 0.0, 0.0);
	pts->InsertNextPoint(1.0, 0.0, 0.0);
	pts->InsertNextPoint(1.0, 1.0, 0.0);
	pts->InsertNextPoint(0.0, 1.0, 0.0);
	pts->InsertNextPoint(2.0, 0.0, 0.0);
 
	vtkSmartPointer<vtkCellArray> vertices = vtkSmartPointer<vtkCellArray>::New();
 
	for (int i = 0; i < 5; i++) {
		vtkIdType pt[1] = { i };
		vertices->InsertNextCell(1, pt);
	}
 
	vtkSmartPointer<vtkPolyData> polyData = vtkSmartPointer<vtkPolyData>::New();
	polyData->SetPoints(pts);
	polyData->SetVerts(vertices);
 
	//标量属性
	vtkSmartPointer<vtkFloatArray> cellScalars = vtkSmartPointer<vtkFloatArray>::New();
 
	for (int i = 0; i < 9; i++)	{
		cellScalars->InsertNextValue(i + 1); //九个索引
	}
 
	polyData->GetCellData()->SetScalars(cellScalars);
 
	vtkSmartPointer<vtkLookupTable> lut = vtkSmartPointer<vtkLookupTable>::New();
	lut->SetNumberOfTableValues(10);
	lut->Build();
	lut->SetTableValue(0, 0, 0, 0, 1);
	 
		for (int i = 1; i < 6; i++)
		{
			lut->SetTableValue(i, 0.0000, 0.0, 0, 1);
		}
 
	vtkSmartPointer<vtkPolyDataMapper> mapper =vtkSmartPointer<vtkPolyDataMapper>::New();
	mapper->SetInputData(polyData);
	mapper->SetScalarRange(0, 5);
	mapper->SetLookupTable(lut);
 
	vtkSmartPointer<vtkActor> actor =vtkSmartPointer<vtkActor>::New();
	actor->SetMapper(mapper);
	actor->GetProperty()->SetPointSize(3);
 
	vtkSmartPointer<vtkRenderer> render =vtkSmartPointer<vtkRenderer>::New();
	render->AddActor(actor);
	render->SetBackground(0.0, 0.0, 0.0);
 
	vtkSmartPointer<vtkRenderWindow> rw =vtkSmartPointer<vtkRenderWindow>::New();
	rw->AddRenderer(render);
	rw->SetSize(320, 320);
 
	vtkSmartPointer<vtkRenderWindowInteractor> rwi = vtkSmartPointer<vtkRenderWindowInteractor>::New();
	rwi->SetRenderWindow(rw);
	rwi->Start();
 
	return 0;
}
 

参考：

https://www.cnblogs.com/ybqjymy/p/13984752.html

https://blog.csdn.net/qq_34600424/article/details/106662611

 VTK  形状有时可能是 polydata ，当需要将两个或者多个数据进行合并显示。

可以使用类是 vtkAppendPolyData，输入多个数据，直接 update() 就可以得到想要的结果。

如果去掉重复点可以使用 vtkCleanPolyData 的对象进行基本的数据处理；

#include <vtkSmartPointer.h>
#include <vtkPolyData.h>
#include <vtkFloatArray.h>
#include <vtkCellData.h>
#include <vtkLookupTable.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
 
#include <vtkSmartPointer.h>
#include <vtkLineSource.h>
#include <vtkTubeFilter.h>
#include <vtkConeSource.h>
#include <vtkAppendPolyData.h>
#include <vtkCleanPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkPointData.h>
#include <vtkLine.h>
 
int main(){
 
	//Create a cone
	vtkSmartPointer<vtkConeSource> coneSource =
		vtkSmartPointer<vtkConeSource>::New();
	coneSource->SetCenter(0, 0, 0);
	coneSource->SetRadius(2);
	coneSource->SetHeight(10);
	coneSource->SetResolution(50);
	coneSource->Update();
 
	vtkIntArray *scalars = vtkIntArray::New();
	vtkPointData *conePointDataPointer = coneSource->GetOutput()->GetPointData();
	vtkPolyData *conePolyDataPointer = coneSource->GetOutput();
	scalars->SetNumberOfTuples(conePolyDataPointer->GetNumberOfPoints());
	scalars->SetNumberOfComponents(1);
	for (int i = 0; i < conePolyDataPointer->GetNumberOfPoints(); i++)
	{
		scalars->SetTuple1(i, 1);
	}
	conePointDataPointer->SetScalars(scalars);
	// second 
	vtkSmartPointer<vtkLineSource> line = vtkSmartPointer<vtkLineSource>::New();
	line->SetPoint1(1.0, 0, 0);
	line->SetPoint2(0, 1.0, 20);
 
	vtkSmartPointer<vtkTubeFilter> tube = vtkSmartPointer<vtkTubeFilter>::New();
	tube->SetInputConnection(line->GetOutputPort());
	tube->SetRadius(2);
	tube->SetNumberOfSides(50);
	tube->SetCapping(1);
	tube->Update();
	vtkIntArray *scalarstube = vtkIntArray::New();
	vtkPointData *tubePointDataPointer = tube->GetOutput()->GetPointData();
	vtkPolyData *tubePolyDataPointer = tube->GetOutput();
	scalarstube->SetNumberOfTuples(tubePolyDataPointer->GetNumberOfPoints());
	scalarstube->SetNumberOfComponents(1);
	for (int i = 0; i < tubePolyDataPointer->GetNumberOfPoints(); i++)
	{
		scalarstube->SetTuple1(i, 0);
	}
	tubePointDataPointer->SetScalars(scalarstube);
 
	// combine two poly data
	vtkSmartPointer<vtkAppendPolyData> appendFilter =
		vtkSmartPointer<vtkAppendPolyData>::New();
	appendFilter->AddInputData(tube->GetOutput());
	appendFilter->AddInputData(coneSource->GetOutput());
	appendFilter->Update();
	// Remove any duplicate points.
	//vtkSmartPointer<vtkCleanPolyData> cleanFilter =
	//	vtkSmartPointer<vtkCleanPolyData>::New();
	//cleanFilter->SetInputConnection(appendFilter->GetOutputPort());
	//cleanFilter->Update();
 
	//Create a mapper and actor
	vtkSmartPointer<vtkPolyDataMapper> appendmapper =
		vtkSmartPointer<vtkPolyDataMapper>::New();
	appendmapper->SetInputConnection(appendFilter->GetOutputPort());
 
	vtkSmartPointer<vtkActor> appendactor =
		vtkSmartPointer<vtkActor>::New();
	appendactor->SetMapper(appendmapper);
 
 
 
	//Create a renderer, render window, and interactor
	vtkSmartPointer<vtkRenderer> renderer =
		vtkSmartPointer<vtkRenderer>::New();
	vtkSmartPointer<vtkRenderWindow> renderWindow =
		vtkSmartPointer<vtkRenderWindow>::New();
	renderWindow->AddRenderer(renderer);
	vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
		vtkSmartPointer<vtkRenderWindowInteractor>::New();
	renderWindowInteractor->SetRenderWindow(renderWindow);
 
	//Add the actors to the scene
	renderer->AddActor(appendactor);
	renderer->SetBackground(.3, .2, .1); // Background color dark red
 
	//Render and interact
	renderWindow->Render();
	renderWindowInteractor->Start();
 
 
 
	return 0;
}
 

 源：

https://blog.csdn.net/Jane_yuhui/article/details/83893218