VTKでPointCloudを表示（改）

#include <iostream>

//VTK_MODULE_INITに必要
#include <vtkAutoInit.h>


#include <vtkSmartPointer.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>

#include <vtkDoubleArray.h>
#include <vtkPointData.h>
#include <vtkActor.h>

#include <vtkCellArray.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>


#pragma comment(lib,"opengl32.lib")
#pragma comment(lib,"psapi.lib")
#pragma comment(lib,"dbghelp.lib")
#pragma comment(lib,"ws2_32.lib")


//必須
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkInteractionStyle);

void create(
    
    vtkSmartPointer<vtkPoints> points, 
    vtkSmartPointer<vtkDoubleArray> colors, 
    vtkSmartPointer<vtkCellArray> cells

) {

    for (size_t i = 0; i < 100000; i++) {

        double x = (double)rand() / (double)RAND_MAX;
        double y = (double)rand() / (double)RAND_MAX;
        double z = (double)rand() / (double)RAND_MAX;

        points->InsertNextPoint(x, y, z);  // 座標追加
        colors->InsertNextTuple3(x, y, z); // 色情報追加

        cells->InsertNextCell(1);  // 要素数
        cells->InsertCellPoint(i); // 頂点インデックスを追加

    }
}

vtkSmartPointer<vtkActor> createActor() {

    // 頂点配列
    vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();

    // 色情報の配列
    vtkSmartPointer<vtkDoubleArray> colors = vtkSmartPointer<vtkDoubleArray>::New();
    colors->SetNumberOfComponents(3);
    colors->SetName("Colors");

    // 頂点インデクスの配列
    vtkSmartPointer<vtkCellArray> cells = vtkSmartPointer<vtkCellArray>::New();

    create(points, colors, cells);

    ///////////////////////////////////////////////////

    // --- vtkPolyData作成 ---
    auto polydata = vtkSmartPointer<vtkPolyData>::New();
    polydata->SetPoints(points);
    polydata->SetVerts(cells);
    polydata->GetPointData()->SetScalars(colors);

    // --- actor作成 ---
    auto mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
    mapper->SetInputData(polydata);

    vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
    actor->SetMapper(mapper);

    return actor;

}

int main(int /*argc*/, char** /*argv*/)
{
    auto actor = createActor();

    auto renderer = vtkSmartPointer<vtkRenderer>::New();
    renderer->AddActor(actor);
    renderer->ResetCamera();

    //////////////////////////////////////
    auto interactor = vtkSmartPointer<vtkRenderWindowInteractor>::New();

    //////////////////////////////////////
    auto renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
    renderWindow->AddRenderer(renderer);
    renderWindow->SetInteractor(interactor);
    renderWindow->Render();

    interactor->Start(); //イベントループへ入る

    return 0;
}