VTK lookuptable创建颜色映射表

新建对象的方式有两种一种是智能指针，一种就是new+delete

本文也不完全是自己原创的东西，也是参考别人的BLOG。

首先，定义一个立方体，点+ 面；

而后，为立方体的每一个点设置属性值；

// 设定每个顶点的标量值
cube->GetPointData()->SetScalars(scalars);

在建立颜色表的同时需要连接属性值/标量值~~~

// 设置颜色表中的颜色
pColorTable->SetNumberOfColors(8);
/*pColorTable->SetTableValue(0,1.0,0.0,0.0,1.0);*/
pColorTable->SetTableValue(0,1.0,0.0,0.0,1.0);
pColorTable->SetTableValue(1,0.0,1.0,0.0,1.0);
pColorTable->SetTableValue(2,1.0,1.0,0.0,1.0);
pColorTable->SetTableValue(3,0.0,0.0,1.0,1.0);
pColorTable->SetTableValue(4,1.0,0.0,1.0,1.0);
pColorTable->SetTableValue(5,0.0,1.0,1.0,1.0);
pColorTable->SetTableValue(6,1.0,1.0,1.0,1.0);
pColorTable->SetTableValue(7,0.0,0.0,0.0,1.0);
pColorTable->Build();

颜色映射的过程主要包括以下步骤：
    1）定义颜色表，在颜色表中用数组保存所定义的颜色组分（红、绿、蓝）。
     2）将颜色表和属性数据关联。
     3）根据属性数据的最大、最小值建立颜色索引

#include "stdafx.h"

#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkInteractionStyle);

#include "vtkActor.h"
#include "vtkCamera.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>

int _tmain(int argc, _TCHAR* argv[])
{
   int i;
   //定义立方体的顶点坐标
   static float x[8][3]={{0,0,0}, {1,0,0}, {1,1,0}, {0,1,0},{0,0,1}, {1,0,1}, {1,1,1}, {0,1,1}};
   //定义单元，每4个顶点建立一个四边形单元，共计6个单元
   static vtkIdType pts[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}};
   //创建对象
   vtkPolyData *cube = vtkPolyData::New();
   vtkPoints *points = vtkPoints::New();
   vtkCellArray *polys = vtkCellArray::New();
   //存储标量值
   vtkFloatArray *scalars = vtkFloatArray::New();
   //存储顶点
   for(i=0;i<8;i++)points->InsertPoint(i,x[i]);
   //设定单元
   for(i=0;i<6;i++)polys->InsertNextCell(4,pts[i]);
   //设定每个顶点的标量值
   for(i=0;i<8;i++)scalars->InsertTuple1(i,i);
   //创建多边形数据
   cube->SetPoints(points);
   //设定单元类型为多边形
   cube->SetPolys(polys);
   //设定每个顶点的标量值
   cube->GetPointData()->SetScalars(scalars);
   points->Delete();
   polys->Delete();
   scalars->Delete();
   //定义颜色映射表
   vtkLookupTable *pColorTable=vtkLookupTable::New();
   //设置颜色表中的颜色
   pColorTable->SetNumberOfColors(8);
   /*pColorTable->SetTableValue(0,1.0,0.0,0.0,1.0);*/
   pColorTable->SetTableValue(0,1.0,0.0,0.0,1.0);
   pColorTable->SetTableValue(1,0.0,1.0,0.0,1.0);
   pColorTable->SetTableValue(2,1.0,1.0,0.0,1.0);
   pColorTable->SetTableValue(3,0.0,0.0,1.0,1.0);
   pColorTable->SetTableValue(4,1.0,0.0,1.0,1.0);
   pColorTable->SetTableValue(5,0.0,1.0,1.0,1.0);
   pColorTable->SetTableValue(6,1.0,1.0,1.0,1.0);
   pColorTable->SetTableValue(7,0.0,0.0,0.0,1.0);
   pColorTable->Build();
   //数据映射
   vtkPolyDataMapper *cubeMapper = vtkPolyDataMapper::New();
   cubeMapper->SetInputData(cube);
   cubeMapper->SetScalarRange(0,7);
   cubeMapper->SetLookupTable(pColorTable);
   vtkActor *cubeActor = vtkActor::New();
   cubeActor->SetMapper(cubeMapper);
   //绘制
   vtkCamera *camera = vtkCamera::New();
   camera->SetPosition(1,1,1);
   camera->SetFocalPoint(0,1,0);
   vtkRenderer *renderer = vtkRenderer::New();
   vtkRenderWindow *renWin = vtkRenderWindow::New();
   renWin->AddRenderer(renderer);
   vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();
   iren->SetRenderWindow(renWin);
   renderer->AddActor(cubeActor);
   renderer->SetActiveCamera(camera);
   renderer->ResetCamera();
   renderer->SetBackground(1,1,1);
   renWin->SetSize(300,300);
   renWin->Render();
   iren->Start();
   //删除对象
   cube->Delete();
   cubeMapper->Delete();
   cubeActor->Delete();
   camera->Delete();
   renderer->Delete();
   renWin->Delete();
   iren->Delete();
   pColorTable->Delete();

   return 0;

}
结果图：

VTK lookuptable创建颜色映射表

转：https://blog.csdn.net/Jane_yuhui/article/details/51970736