vtkpolydata圖形着色

2020-06-10

顏色可以直接作爲一種標量屬性數據，設置到相應的點或者單元數據中，這是最直接的一種圖形着色方式。

1.需求

根據vtkLookupTable爲點設置相對應的顏色，在這裏我們需要首先爲點設置標量屬性值。

2.代碼

#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);

	//標量屬性
	vtkSmartPointer<vtkFloatArray> cellScalars = vtkSmartPointer<vtkFloatArray>::New();

	for (int i = 0; i < 9; i++)	{
		cellScalars->InsertNextValue(i + 1); //九個索引
	}

	polyData->GetCellData()->SetScalars(cellScalars);

	vtkSmartPointer<vtkLookupTable> lut = vtkSmartPointer<vtkLookupTable>::New();
	lut->SetNumberOfTableValues(10);
	lut->Build();
	lut->SetTableValue(0, 0, 0, 0, 1);
	lut->SetTableValue(1, 0.8900, 0.8100, 0.3400, 1);
	lut->SetTableValue(2, 1.0000, 0.3882, 0.2784, 1);
	lut->SetTableValue(3, 0.9608, 0.8706, 0.7020, 1);
	lut->SetTableValue(4, 0.9020, 0.9020, 0.9804, 1);
	lut->SetTableValue(5, 1.0000, 0.4900, 0.2500, 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;
}

3.結果

如果什麼也沒有顯示可以用鼠標滾輪進行縮放一下