Top, Left, Right, Bottom, Back View.

Support
, ,
1

Hello,

ex) Top View
( CloudCompare

I programmed the code below to implement CloudCompare Top View.
But it looks like a Top View, but I don’t think it’s a perfect Top View.
( It seems to be tilted very slightly. )

Let me know what I made a mistake.

vtkCamera *m_vtkCamera;
m_vtkCamera = m_vtkRenderer->GetActiveCamera();
m_vtkCamera->SetFocalPoint(0, 0, 0);
m_vtkCamera->SetViewUp(0, 0, 0);
m_vtkCamera->SetPosition(0, 0, 1);

BR

2

Hi, Seram,

This is how I do “look at plane” (the 3 first button in your case):

void View3DWidget::onLookAtXY()
{
    //_renderer->ResetCamera();
    double *fp = _rendererMainScene->GetActiveCamera()->GetFocalPoint();
    double *p = _rendererMainScene->GetActiveCamera()->GetPosition();
    double dist
        = std::sqrt((p[0] - fp[0]) * (p[0] - fp[0]) + (p[1] - fp[1]) * (p[1] - fp[1])
                    + (p[2] - fp[2]) * (p[2] - fp[2]));
    _rendererMainScene->GetActiveCamera()->SetPosition(fp[0], fp[1], fp[2] + dist);
    _rendererMainScene->GetActiveCamera()->SetViewUp(0.0, 1.0, 0.0);
    // redraw the scene
    _vtkwidget->GetRenderWindow()->Render();
}

void View3DWidget::onLookAtXZ()
{
    double *fp = _rendererMainScene->GetActiveCamera()->GetFocalPoint();
    double *p = _rendererMainScene->GetActiveCamera()->GetPosition();
    double dist
        = std::sqrt((p[0] - fp[0]) * (p[0] - fp[0]) + (p[1] - fp[1]) * (p[1] - fp[1])
                    + (p[2] - fp[2]) * (p[2] - fp[2]));
    _rendererMainScene->GetActiveCamera()->SetPosition(fp[0], fp[1] - dist, fp[2]);
    _rendererMainScene->GetActiveCamera()->SetViewUp(0.0, 0.0, 1.0);
    // redraw the scene
    _vtkwidget->GetRenderWindow()->Render();
}

void View3DWidget::onLookAtYZ()
{
    double *fp = _rendererMainScene->GetActiveCamera()->GetFocalPoint();
    double *p = _rendererMainScene->GetActiveCamera()->GetPosition();
    double dist
        = std::sqrt((p[0] - fp[0]) * (p[0] - fp[0]) + (p[1] - fp[1]) * (p[1] - fp[1])
                    + (p[2] - fp[2]) * (p[2] - fp[2]));
    _rendererMainScene->GetActiveCamera()->SetPosition(fp[0] + dist, fp[1], fp[2]);
    _rendererMainScene->GetActiveCamera()->SetViewUp(0.0, 0.0, 1.0);
    // redraw the scene
    _vtkwidget->GetRenderWindow()->Render();
}

For the other 3 buttons, you need to swap the signs of the sums/diffs in the _rendererMainScene->GetActiveCamera()->SetPosition() calls (e.g. from fp[0] + dist to fp[0] - dist);

I hope this helps,

regards,

Paulo

1 Like
4

Hi Paulo

I tried applying the code, but it’s still slightly tilted.
Is there any way to look like CloudCompare?

T
T3011×804 180 KB

BR
Seram

5

This looks more like the perspective of the camera rather than the camera position, you can set the projection to be parallel by adding:

m_vtkCamera->ParallelProjectionOn();

You can always toggle this option too.

6

Hi Fraseyboo

Thanks for the answer.
Thanks to that, the problem was solved.

BR
Seram