[vtkusers] How to converting coordinates from dataset to view? - Part two

[Wagner Sales]

Hi all,

The following message was sent in some minutes ago.
I'm trying to show marked points in a 2D view from a dataset in 3D view of
segmented data from this dataset. To explain more:
a) I have a DICOM dataset
b) In 2D view I was marked some points to use in segmentation, done by ITK.
The segmentation works fine, then I think my points are marked ok.
c) After segmentation, I extract the polydata and show in a 3D view.
d) Then, I try to create new points in 2D view and show in 3D. The points
are created, but in 3D appears in a different location.
Well, I think I need to convert the coordinates from the point and after
that set manually the position of the point (a vtkActor) in 3D view.

Are I'm correct? If yes, how to convert these coordinates? Are another more
simple approach?

Well, taking a look at my VTK book and some examples, I think I need to
translate the dataset to global coordinates. This are done by the following
code:

double *Point::translateCoordinates(int x, int y, int z)
{
       // m_CurrentImageData are a vtkImageData instance
        if(!m_CurrentImageData)
        {
                xyzCoords[0] = 0.0;
                xyzCoords[1] = 0.0;
                xyzCoords[2] = 0.0;
                return xyzCoords;
        }
        q[0] = x;
        q[1] = y;
        q[2] = z;
        cellNum = m_CurrentImageData->ComputeCellId(q);
        subID = m_CurrentImageData->GetCell( cellNum
)->GetParametricCenter(paraCoords);
        int &subIDadd = subID;
        m_CurrentImageData->GetCell(cellNum)->EvaluateLocation(subIDadd,
paraCoords,
        xyzCoords, vtkcellweights);
        return xyzCoords;
}

Then I'm trying to set the actor position using xyzCoords, but not working (
the point are in wrong position yet ). Any help?

Thks in advance,

Wagner Sales
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20080514/00c21375/attachment.htm>