[vtkusers] Clipping Planes

[Jeff Lee]

Hi James.
Have you tried vtkWarpVector instead of manually shifting your points? 
If you still have problems with the clipping range, it at least takes 
your code out of the loop.
-Jeff

James Robinson wrote:

> John,
>
> Many thanks for replying. I have tried EVERYTHING. I have even tried 
> reloading all the props into the renderer. I have checked the altered 
> bounds on everything from the vtkUnstructuredGrid to the vtkPoints* 
> pNodalGeometry. None of the bounds are altered after the change 
> (which, I would imagine, is why the resetting of the clip planes has 
> no effect). My workaround is:
>
> void CSampleView::ResetCameraClippingRange(BOOL ShowDisplacement)
>
> {
>
> // float bounds[6] ;
>
> // Renderer->ComputeVisiblePropBounds(bounds) ;
>
> // Renderer->ResetCameraClippingRange() ;
>
> // TODO: add construction code here
>
> vtkInteractorStyleSwitch* pStyle = 
> (vtkInteractorStyleSwitch*)Interactor->GetInteractorStyle() ;
>
> if (ShowDisplacement)
>
> {
>
> pStyle->AutoAdjustCameraClippingRangeOff() ;
>
> vtkCamera* pCamera = Renderer->GetActiveCamera() ;
>
> pCamera->SetClippingRange(0.001, 1000.) ; // Arbitrary – this could be 
> automated
>
> } else
>
> {
>
> pStyle->AutoAdjustCameraClippingRangeOn() ;
>
> }
>
> }
>
> which I call every time the displacement view option is chosen. Note 
> that it was at this level that I tried to ResetCameraClippingRange 
> (both with bounds computed and not), but to no avail.
>
> Any other suggestions welcomed.
>
> Regards,
>
> Jim
>
> *James C Robinson*, PhD, Chartered Engineer,
>
> + 42 Rivergrove,
>
> Glanmire,
>
> Co. Cork,
>
> Eire
>
> ' +353 21 4822028
>
> +353 87 2393010
>
> 6 +353 21 4822028
>
> - j.robinson at kepler-systems.com
>
> ------------------------------------------------------------------------
>
> *From:* John Biddiscombe [mailto:jbiddiscombe at skippingmouse.co.uk]
> *Sent:* 11 August 2004 12:20
> *To:* j.robinson at kepler-systems.com; Vtk Users
> *Subject:* Re: [vtkusers] Clipping Planes
>
> After calling AddDisplacement(...) you are calling 
> resetCameralippingRage() yes? If not. try it.
>
> JB
>
>     ----- Original Message -----
>
>     *From:* James Robinson <mailto:j.robinson at kepler-systems.com>
>
>     *To:* Vtk Users <mailto:vtkusers at vtk.org>
>
>     *Sent:* Wednesday, August 11, 2004 11:24 AM
>
>     *Subject:* [vtkusers] Clipping Planes
>
>     Dear All,
>
>     I am having trouble (again) with clipping planes. I am trying to
>     create a viewer to view results of an FE analysis. Part of the
>     results are the displacements at the nodes of the finite element
>     mesh. I read in the FE mesh into a vtkUnstructuredGrid with the
>     displacements as a vector field. I then create a displaced
>     geometry by adding them to the vtkUnstructuredGrid geometry as
>     follows:
>
>     void CSampleDoc::AddDisplacement(float factor)
>
>     { vtkFloatArray *pDisplacement =
>     (vtkFloatArray*)this->pUnstructuredGrid->GetPointData()->GetVectors()
>     ;
>
>     vtkPoints* pNodalGeometry = this->pUnstructuredGrid->GetPoints() ;
>
>     if (pDisplacement==NULL)
>
>     { AfxMessageBox("No displacement set") ;
>
>     return ;
>
>     }
>
>     float newcoords[3] ;
>
>     float* x ;
>
>     float* delta ;
>
>     for (int i = 0; i < pNodalGeometry->GetNumberOfPoints(); i++)
>
>     {
>
>     x = pNodalGeometry->GetPoint(i) ;
>
>     delta = pDisplacement->GetTuple(i) ;
>
>     for (int j = 0; j < 3; j++)
>
>     { newcoords[j] = x[j] + factor*delta[j] ;
>
>     }
>
>     pNodalGeometry->SetPoint(i,newcoords) ;
>
>     }
>
>     this->pUnstructuredGrid->Update() ;
>
>     this->pGeometry->SetInput(pUnstructuredGrid) ;
>
>     this->pMeshMapper->SetInput(pGeometry->GetOutput());
>
>     this->pMeshMapper->Update() ;
>
>     this->pMeshActor->SetMapper(this->pMeshMapper) ;
>
>     }
>
>     This works (with some other quirky behaviour which I have
>     circumvented). But a problem that I am having difficulty with is
>     that the clipping planes remain as if the geometry hadn’t been
>     altered. Thus, as I rotate the object (in trackball camera mode)
>     the displaced object disappears. I have checked the bounds of the
>     viewable objects (using Renderer->ComputeVisiblePropBounds(bounds)
>     ;) and they are unaltered – thus all the AutoClipping is thrown
>     out of whack. It may very well be that (a) I am doing things that
>     are not meant to be catered for in vtk or (b) there is a better
>     (preferably simpler) way of achieving this effect.
>
>     All suggestions gratefully welcomed.
>
>     Jim
>
>     *James C Robinson*, PhD, Chartered Engineer,
>
>     + 42 Rivergrove,
>
>     Glanmire,
>
>     Co. Cork,
>
>     Eire
>
>     ' +353 21 4822028
>
>     +353 87 2393010
>
>     6 +353 21 4822028
>
>     - j.robinson at kepler-systems.com
>
>     ------------------------------------------------------------------------
>
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