VTK顯示箭頭

#ifndef VTKHSWARRORWIDGET_H
#define VTKHSWARRORWIDGET_H

/*
 * ModuleName: vtkRoboArrowWidget
 * Description: 實現箭頭
 * Author: hsw
 * Date: 2020-03-22
 *
 */
#include <vtkSmartPointer.h>
#include <vtkArrowSource.h>
#include <vtkDataSetMapper.h>
#include <vtkMinimalStandardRandomSequence.h>
#include <vtkMatrix4x4.h>
#include <vtkTransform.h>
#include <vtkTransformPolyDataFilter.h>

class vtkHSWArrorWidget
{
public:
    vtkHSWArrorWidget();
    ~vtkHSWArrorWidget();
public:
    vtkSmartPointer<vtkDataSetMapper> createArrow(double* start, double* end);
private:
    vtkSmartPointer<vtkArrowSource>   _arrowSource;
    vtkSmartPointer<vtkDataSetMapper> _arrowMapper;
};

#endif // VTKHSWARRORWIDGET_H

 

#include "vtkhswarrorwidget.h"

vtkHSWArrorWidget::vtkHSWArrorWidget()
{
    // TODO...
}

vtkHSWArrorWidget::~vtkHSWArrorWidget()
{
    // TODO...
}

vtkSmartPointer<vtkDataSetMapper> vtkHSWArrorWidget::createArrow(double* start, double* end)
{
    _arrowSource = vtkSmartPointer<vtkArrowSource>::New();

    // Compute a basis
    double normalizedX[3];
    double normalizedY[3];
    double normalizedZ[3];

    // The X axis is a vector from start to end
    vtkMath::Subtract(end, start, normalizedX);
    double length = vtkMath::Norm(normalizedX);
    vtkMath::Normalize(normalizedX);

    // The Z axis is an arbitrary vector cross X
    vtkSmartPointer<vtkMinimalStandardRandomSequence> rng =
            vtkSmartPointer<vtkMinimalStandardRandomSequence>::New();
    rng->SetSeed(8775070);
    double arbitrary[3];
    for (auto i = 0; i < 3; ++i)
    {
        rng->Next();
        arbitrary[i] = rng->GetRangeValue(-10, 10);
    }
    vtkMath::Cross(normalizedX, arbitrary, normalizedZ);
    vtkMath::Normalize(normalizedZ);

    // The Y axis is Z cross X
    vtkMath::Cross(normalizedZ, normalizedX, normalizedY);
    vtkSmartPointer<vtkMatrix4x4> matrix =
            vtkSmartPointer<vtkMatrix4x4>::New();

    // Create the direction cosine matrix
    matrix->Identity();
    for (auto i = 0; i < 3; i++)
    {
        matrix->SetElement(i, 0, normalizedX[i]);
        matrix->SetElement(i, 1, normalizedY[i]);
        matrix->SetElement(i, 2, normalizedZ[i]);
    }

    // Apply the transforms
    vtkSmartPointer<vtkTransform> transform =
            vtkSmartPointer<vtkTransform>::New();
    transform->Translate(start);
    transform->Concatenate(matrix);
    transform->Scale(length, length, length);

    // Transform the polydata
    vtkSmartPointer<vtkTransformPolyDataFilter> transformPD =
            vtkSmartPointer<vtkTransformPolyDataFilter>::New();
    transformPD->SetTransform(transform);
    transformPD->SetInputConnection(_arrowSource->GetOutputPort());

    _arrowMapper = vtkSmartPointer<vtkDataSetMapper>::New();

    _arrowMapper->SetInputConnection(transformPD->GetOutputPort());

    return _arrowMapper;
}