[vtkusers] [Edit]: UGrid volume ray cast Bug?
Juan José Aja Fernández
juan.aja at gmail.com
Thu Apr 6 10:24:49 EDT 2006
Yep, that did the trick.
This deserves a bug report?
Thanks a lot Randall, you've been most helpful.
Juan
On 4/6/06, Randall Hand <randall.hand at gmail.com> wrote:
>
> OK, I'm seeing the same glitch here on my end.. That is an odd one.. The
> only thing I know to attribute it to is some type of interpolation within
> the colormap. If you switch from vtkUnstructuredGridVolumeRayCastMapper to
> vtkProjectedTetrahedraMapper then it works perfectly. Also, if you switch
> from the colormap approach to the 4-component approach I mentioned last
> night, then it works just fine. At this point, it does seem to be some kind
> of issue in the RayCastMapper.
>
> I'm gonna dig a little deeper, I'll let you know what I find, if
> anything. Also, just fyi, you don't need to declare the OpenGL objects
> directly, the object factories know when to create the OpenGL ones vs the
> Mesa ones just fine :)
>
> As promised, code for the 4-component scalar shown below:
>
> #include "vtkVoxel.h"
> #include "vtkCellData.h"
> #include " vtkRenderer.h"
> #include "vtkPoints.h"
> #include "vtkUnstructuredGrid.h"
> #include "vtkRenderWindow.h"
> #include "vtkRenderWindowInteractor.h"
> #include "vtkColorTransferFunction.h "
> #include "vtkPiecewiseFunction.h"
> #include "vtkVolume.h"
> #include "vtkVolumeProperty.h"
> #include "vtkUnstructuredGridWriter.h"
> #include "vtkDoubleArray.h"
> #include "vtkDataSetTriangleFilter.h"
> #include "vtkUnstructuredGridVolumeRayCastMapper.h"
> #include "vtkUnstructuredGridVolumeRayCastFunction.h"
> #include "vtkImageData.h"
> #include "vtkDataSetToImageFilter.h"
> #include "stdio.h"
> #include "iostream.h"
> #include "fstream.h"
> #include "string.h"
> #include "vtkOpenGLRenderer.h "
> #include "vtkXOpenGLRenderWindow.h"
> #include "vtkXRenderWindowInteractor.h"
>
>
> int main(int argc, char *dim[])
> {
>
> int dim_x = atoi(dim[1]);
> int dim_y = atoi(dim[1]);
> int dim_z = atoi(dim[1]);
> int i, j, k;
> int no_points = dim_x * dim_x * dim_x;
> int no_voxels = (dim_x-1) * (dim_x-1) * (dim_x-1);
>
> vtkPoints *points = vtkPoints::New();
> points->SetNumberOfPoints(no_points);
> points->SetDataTypeToDouble();
>
> for(k=0; k< dim_z; k++)
> for(j=0; j< dim_y; j++)
> for(i=0; i< dim_x; i++)
> points->InsertNextPoint(i, j, k);
>
> vtkDoubleArray *pts = vtkDoubleArray::New();
> pts->SetNumberOfComponents(4);
> pts->SetName("pts");
>
> for(i=0; i < no_voxels; i++) {
> if (i & 0x01)
> pts->InsertNextTuple4(1,0,0,0.9);
> else
> pts->InsertNextTuple4(0,1,0, 0.9);
> }
>
> vtkUnstructuredGrid *grid = vtkUnstructuredGrid::New();
>
>
> //To create the grid we need to know if we are in any of the
> //cube limits (height, width, depth), to prevent from adding
> //inexistant cells
> j=0;
> k=0;
> int w = 0;
> int count = 0;
> vtkVoxel *v = vtkVoxel::New();
>
> for(i=0; i< (no_points - ((dim_x * dim_x) + (dim_x + 1))); i++) {
> if(j != dim_x - 1 && k!= dim_x - 1) {
> (v->GetPointIds())->SetId(0, i);
> (v->GetPointIds())->SetId(1, i+1);
> (v->GetPointIds())->SetId(2, i+dim_x);
> (v->GetPointIds())->SetId(3, i+dim_x+1);
> (v->GetPointIds())->SetId(4, i + (dim_x * dim_y));
> (v->GetPointIds())->SetId(5, i + (dim_x * dim_y) + 1);
> (v->GetPointIds())->SetId(6, i + (dim_x * dim_y) + dim_x);
> (v->GetPointIds())->SetId(7, i + (dim_x * dim_y) + dim_x + 1);
> grid->InsertNextCell(v->GetCellType(), v->GetPointIds());
>
> j++;
> count++;
> }
> else {
> if(j == dim_x-1) {
> j=0;
> k++;
> if(k == dim_x-1) {
> j=0;
> k=0;
> i = i+dim_x;
> w++;
> }
> }
> }
> }
> grid->SetPoints(points);
>
> vtkCellData *cd = grid->GetCellData();
> cd->SetNumberOfTuples(no_voxels);
> cd->SetScalars(pts);
>
> vtkRenderer *renderer = vtkRenderer::New();
> vtkRenderWindow *renwin = vtkRenderWindow::New();
> vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();
>
>
> renwin->AddRenderer(renderer);
> iren->SetRenderWindow(renwin);
>
> vtkVolumeProperty *vp = vtkVolumeProperty::New();
> // vp->SetColor(funtrans);
> // vp->SetScalarOpacity(funop);
> vp->IndependentComponentsOff();
>
>
> vtkUnstructuredGridVolumeRayCastMapper *vrcm =
> vtkUnstructuredGridVolumeRayCastMapper::New();
>
> vtkDataSetTriangleFilter *filter = vtkDataSetTriangleFilter::New();
> filter->SetInput(grid);
>
> vrcm->SetInput(filter->GetOutput());
>
> vtkVolume *volume = vtkVolume::New();
> volume->SetMapper(vrcm);
> volume->SetProperty(vp);
>
> renderer->AddActor(volume);
>
> renwin->Render();
> iren->Start();
> }
>
>
>
>
> On 4/5/06, Randall Hand <randall.hand at gmail.com> wrote:
> >
> > If you look at the documentation for vtkVolumeProperty around the
> > SetIndependantComponents stuff : http://www.vtk.org/doc/release/5.0/html/a02182.html#z4350_1
> >
> >
> > I'll play around with it tomorrow morning.. if I can get a working
> > version of your test driver, I'll send it to you for you to check out :)
> >
> >
> > On 4/5/06, Juan José Aja Fernández <juan.aja at gmail.com> wrote:
> > >
> > > Hi, Randall:
> > >
> > > Thanks again for the swift response.
> > >
> > > I haven't tried using point data, first thing tomorrow I will rewrite
> > > the code.
> > >
> > > Your second suggestion was exactly what I was looking for, until now I
> > > didn't know if there was a way to color whithout using a transfer function
> > > (that explains my horrible hack of using the voxel index as a "scalar"). I
> > > skimmed through the docs trying to find something related, and I looked at
> > > vtkScalarsToColors as a possible candidate, but I have my doubts: ¿How can I
> > > create a RGBA scalar field and how can this be used as the color function in
> > > the mapper?
> > >
> > >
> > > Thanks a lot,
> > >
> > > Juan.
> > >
> > >
> > >
> > > On 4/5/06, Randall Hand <randall.hand at gmail.com> wrote:
> > > >
> > > > I'll try this out on my end tomorrow, since I'm already neck-deep in
> > > > the Volume Rendering code anyway :)
> > > >
> > > > Just a thought tho, I believe most of the Volume Renderers expect
> > > > Point Data, not Cell Data.. Have you tried using Per-point data?
> > > >
> > > > Also, if you really want to define colors per-point and not via a
> > > > colormap, then if you use a 4-component scalar field you can have it
> > > > directly contain R/G/B/A for volume rendering.
> > > >
> > > > On 4/5/06, Juan José Aja Fernández <juan.aja at gmail.com> wrote:
> > > >
> > > > > (Sorry for the double post, The first url was broken)
> > > >
> > > > Hi, Everyone:
> > > >
> > > > This is the third time I'm posting about this issue, of the previous
> > > > two one remained unanswered and the last one I've got a kind response by
> > > > Randall Hand: http://public.kitware.com/pipermail/vtkusers/2006-February/083786.html
> > > >
> > > >
> > > > who pointed me in the direction of this fixed bug:
> > > >
> > > > http://www.vtk.org/Bug/bug.php?op=show&bugid=2546&pos=3 but the
> > > > problem persists.
> > > >
> > > > I think the vtkUnstructuredGridVolumeRayCastMapper has some serious
> > > > bug (look at the screenshots posted in the thread that Randall answered),
> > > > and to prove It I think I need to post my entire example code:
> > > >
> > > > (Really, I think I'm on to something, specially If you consider that
> > > > the mapper for unstructured grids is fairly new, but I didn't want to litter
> > > > the bug report with false positives).
> > > >
> > > >
> > > > #include "vtkVoxel.h"
> > > > #include "vtkCellData.h"
> > > > #include "vtkRenderer.h"
> > > > #include "vtkPoints.h"
> > > > #include "vtkUnstructuredGrid.h"
> > > > #include "vtkRenderWindow.h"
> > > > #include "vtkRenderWindowInteractor.h"
> > > > #include "vtkColorTransferFunction.h"
> > > > #include "vtkPiecewiseFunction.h"
> > > > #include "vtkVolume.h"
> > > > #include "vtkVolumeProperty.h"
> > > > #include "vtkUnstructuredGridWriter.h"
> > > > #include "vtkDoubleArray.h"
> > > > #include "vtkDataSetTriangleFilter.h"
> > > > #include "vtkUnstructuredGridVolumeRayCastMapper.h"
> > > > #include "vtkUnstructuredGridVolumeRayCastFunction.h"
> > > > #include "vtkImageData.h"
> > > > #include "vtkDataSetToImageFilter.h"
> > > > #include "stdio.h"
> > > > #include "iostream.h"
> > > > #include "fstream.h"
> > > > #include "string.h"
> > > > #include "vtkOpenGLRenderer.h"
> > > > #include "vtkXOpenGLRenderWindow.h"
> > > > #include "vtkXRenderWindowInteractor.h"
> > > >
> > > >
> > > > int main(int argc, char *dim[])
> > > > {
> > > >
> > > > int dim_x = atoi(dim[1]);
> > > > int dim_y = atoi(dim[1]);
> > > > int dim_z = atoi(dim[1]);
> > > > int i, j, k;
> > > > int no_points = dim_x * dim_x * dim_x;
> > > > int no_voxels = (dim_x-1) * (dim_x-1) * (dim_x-1);
> > > >
> > > > vtkPoints *points = vtkPoints::New();
> > > > points->SetNumberOfPoints(no_points);
> > > > points->SetDataTypeToDouble();
> > > >
> > > > for(k=0; k< dim_z; k++)
> > > > for(j=0; j< dim_y; j++)
> > > > for(i=0; i< dim_x; i++)
> > > > points->InsertNextPoint(i, j, k);
> > > >
> > > > vtkDoubleArray *pts = vtkDoubleArray::New();
> > > > pts->SetName("pts");
> > > >
> > > > for(i=0; i < no_voxels; i++)
> > > > pts->InsertNextValue(i);
> > > >
> > > > vtkUnstructuredGrid *grid = vtkUnstructuredGrid::New();
> > > >
> > > > vtkColorTransferFunction *funtrans =
> > > > vtkColorTransferFunction::New();
> > > >
> > > > //To create the grid we need to know if we are in any of the
> > > > //cube limits (height, width, depth), to prevent from adding
> > > > //inexistant cells
> > > > j=0;
> > > > k=0;
> > > > int w = 0;
> > > > int count = 0;
> > > > vtkVoxel *v = vtkVoxel::New();
> > > >
> > > > for(i=0; i< (no_points - ((dim_x * dim_x) + (dim_x + 1))); i++) {
> > > > if(j != dim_x - 1 && k!= dim_x - 1) {
> > > > (v->GetPointIds())->SetId(0, i);
> > > > (v->GetPointIds())->SetId(1, i+1);
> > > > (v->GetPointIds())->SetId(2, i+dim_x);
> > > > (v->GetPointIds())->SetId(3, i+dim_x+1);
> > > > (v->GetPointIds())->SetId(4, i + (dim_x * dim_y));
> > > > (v->GetPointIds())->SetId(5, i + (dim_x * dim_y) + 1);
> > > > (v->GetPointIds())->SetId(6, i + (dim_x * dim_y) + dim_x);
> > > > (v->GetPointIds())->SetId(7, i + (dim_x * dim_y) + dim_x + 1);
> > > > grid->InsertNextCell(v->GetCellType(), v->GetPointIds());
> > > >
> > > > j++;
> > > > count++;
> > > > }
> > > > else {
> > > > if(j == dim_x-1) {
> > > > j=0;
> > > > k++;
> > > > if(k == dim_x-1) {
> > > > j=0;
> > > > k=0;
> > > > i = i+dim_x;
> > > > w++;
> > > > }
> > > > }
> > > > }
> > > > }
> > > > grid->SetPoints(points);
> > > >
> > > > vtkCellData *cd = grid->GetCellData();
> > > > cd->SetNumberOfTuples(no_voxels);
> > > > cd->SetScalars(pts);
> > > >
> > > > int idx = 0;
> > > > while (idx < no_voxels) {
> > > > if (idx%2 == 0 )
> > > >
> > > > funtrans->AddRGBPoint(pts->GetValue(idx), 1, 0, 0);
> > > > else funtrans->AddRGBPoint(pts->GetValue(idx), 0, 1,0);
> > > >
> > > > idx++;
> > > > }
> > > > vtkOpenGLRenderer *renderer = vtkOpenGLRenderer::New();
> > > > vtkXOpenGLRenderWindow *renwin = vtkXOpenGLRenderWindow::New();
> > > > vtkXRenderWindowInteractor *iren =
> > > > vtkXRenderWindowInteractor::New();
> > > >
> > > > renwin->AddRenderer(renderer);
> > > > iren->SetRenderWindow(renwin);
> > > >
> > > > vtkPiecewiseFunction *funop = vtkPiecewiseFunction::New();
> > > > funop->AddPoint(0, 1);
> > > > funop->AddPoint(no_voxels, 1);
> > > >
> > > > vtkVolumeProperty *vp = vtkVolumeProperty::New();
> > > > vp->SetColor(funtrans);
> > > > vp->SetScalarOpacity(funop);
> > > >
> > > > vtkUnstructuredGridVolumeRayCastMapper *vrcm =
> > > > vtkUnstructuredGridVolumeRayCastMapper::New();
> > > >
> > > > vtkDataSetTriangleFilter *filter =
> > > > vtkDataSetTriangleFilter::New();
> > > > filter->SetInput(grid);
> > > >
> > > > vrcm->SetInput(filter->GetOutput());
> > > >
> > > > vtkVolume *volume = vtkVolume::New();
> > > > volume->SetMapper(vrcm);
> > > > volume->SetProperty(vp);
> > > >
> > > > renderer->AddActor(volume);
> > > >
> > > > renwin->Render();
> > > > iren->Start();
> > > > }
> > > >
> > > >
> > > > This will attempt to create a cube with dimensions arg[1] coloring
> > > > odd and even cells with green and red.
> > > > Try it with argv[1] = 6, then argv[1] = 20, see the results.
> > > >
> > > > Is this a bug, or I'm doing things the wrong way?
> > > >
> > > >
> > > > Thanks in advance,
> > > >
> > > > Juan.
> > > >
> > > >
> > > > _______________________________________________
> > > > This is the private VTK discussion list.
> > > > Please keep messages on-topic. Check the FAQ at:
> > > > http://www.vtk.org/Wiki/VTK_FAQ
> > > > Follow this link to subscribe/unsubscribe:
> > > > http://www.vtk.org/mailman/listinfo/vtkusers
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > --
> > > > Randall Hand
> > > > Visualization Scientist,
> > > > ERDC-MSRC Vicksburg, MS
> > > > Homepage: http://www.yeraze.com
> > > >
> > >
> > >
> >
> >
> > --
> > Randall Hand
> > Visualization Scientist,
> > ERDC-MSRC Vicksburg, MS
> > Homepage: http://www.yeraze.com
> >
>
>
>
> --
> Randall Hand
> Visualization Scientist,
> ERDC-MSRC Vicksburg, MS
> Homepage: http://www.yeraze.com
>
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