[vtkusers] vtkFastSplatter broken?

[Cory Quammen]

Richard,

On Wed, Jan 6, 2016 at 11:00 AM, Richard Brown
<richard.j.brown at live.co.uk> wrote:
> Cory,
>
> If possible I’d like to splat them into an existing image.

Makes sense, but vtkFastSplatter takes a vtkImageData input into which
you might splat. One could add a third input that, if present, would
be the image into which splatting occurs. If you wanted to patch VTK
and submit the change, it would likely have a good chance of being
integrated.

> When repeating
> the process many times for a large image, surely it becomes rather slow to
> create a new image each time and set all the other values to zero?

My guess is that the splatting is going to take much longer than
allocating and initializing a new vtkImageData.

Thanks,
Cory

>
> Regards,
> Richard
>
> On 06 Jan 2016, at 15:19, Cory Quammen <cory.quammen at kitware.com> wrote:
>
> Richard,
>
> Not sure what you mean. You are splatting a vtkImageData at the 5
> points you defined into a new image. Do you mean you want to splat
> them into an existing image?
>
> Thanks,
> Cory
>
> On Wed, Jan 6, 2016 at 6:19 AM, Richard Brown
> <richard.j.brown at live.co.uk> wrote:
>
> Cory,
>
> Thanks for the help. Still trying to wrap my head around it though - is
> there any way to splat a pre-existing vtkImageData?
>
> Regards,
> Richard
>
> On 05 Jan 2016, at 21:59, Cory Quammen <cory.quammen at kitware.com> wrote:
>
> Hi Richard,
>
> I think you had two problems in your code:
>
> 1). The vtkFastSplatter was auto-determining the origin and pixel
> spacing of the output image. When you moved the one point around, the
> origin was adjusted so that it was always at the location of the one
> point. This appeared in the renderer as though nothing was happening.
> You can fix this by adding a call to
>
> splatter->SetModelBounds(...)
>
> to some fixed bounding box.
>
> 2). Moving points 2-5 by 1 unit in space won't really be visible in an
> image where the voxel size is also 1 and the splat is relatively
> large. You can fix this by moving the points a further distance.
>
> Here is a modified version of your example where the points show up
> where expected:
>
> /*
> * Copyright 2004 Sandia Corporation.
> * Under the terms of Contract DE-AC04-94AL85000, there is a non-exclusive
> * license for use of this work by or on behalf of the
> * U.S. Government. Redistribution and use in source and binary forms, with
> * or without modification, are permitted provided that this Notice and any
> * statement of authorship are reproduced on all copies.
> */
>
> // Simple test of vtkFastSplatter
> #include "vtkImageData.h"
> #include "vtkImageShiftScale.h"
> #include "vtkFastSplatter.h"
> #include "vtkImageViewer2.h"
> #include "vtkPoints.h"
> #include "vtkPolyData.h"
> #include "vtkRenderer.h"
> #include "vtkRenderWindow.h"
> #include "vtkRenderWindowInteractor.h"
>
> #include "vtkSmartPointer.h"
> #define VTK_CREATE(type, name) \
>
> vtkSmartPointer<type> name = vtkSmartPointer<type>::New()
>
> #include <math.h>
>
> const int SPLAT_IMAGE_SIZE = 100;
>
> int main(int, char *[])
> {
> // For the purposes of this example we'll build the splat image by
> // hand.
>
> VTK_CREATE(vtkImageData, SplatImage);
> SplatImage->SetDimensions(SPLAT_IMAGE_SIZE, SPLAT_IMAGE_SIZE, 1);
> SplatImage->AllocateScalars(VTK_FLOAT, 1);
>
> for (int i = 0; i < SPLAT_IMAGE_SIZE; ++i)
>   {
>   for (int j = 0; j < SPLAT_IMAGE_SIZE; ++j)
>     {
>     double xCoord = 1 - fabs(  (i - SPLAT_IMAGE_SIZE/2)
>                                / (SPLAT_IMAGE_SIZE/2.0) );
>     double yCoord = 1 - fabs(  (j - SPLAT_IMAGE_SIZE/2)
>                                / (SPLAT_IMAGE_SIZE/2.0) );
>
>     SplatImage->SetScalarComponentFromDouble(i, j, 0, 0,
>                                              xCoord * yCoord );
>     }
>   }
>
> VTK_CREATE(vtkPolyData, SplatPoints);
> VTK_CREATE(vtkPoints, Points);
>
> Points->SetNumberOfPoints( 5 );
> double point[3];
>
> // Move the points further
> point[0] = 100;
> point[1] = 100;
> point[2] = 0;
> Points->SetPoint( 0, point );
>
> point[0] = 100;
> point[1] = 0;
> point[2] = 0;
> Points->SetPoint( 1, point );
>
> point[0] = 0;
> point[1] = 100;
> point[2] = 0;
> Points->SetPoint( 2, point );
>
> point[0] = 0;
> point[1] = 0;
> point[2] = 0;
> Points->SetPoint( 3, point );
>
> point[0] = 199;
> point[1] = 199;
> point[2] = 0;
> Points->SetPoint( 4, point );
>
> SplatPoints->SetPoints(Points);
>
> VTK_CREATE(vtkFastSplatter, splatter);
> splatter->SetInputData( SplatPoints );
> splatter->SetOutputDimensions( 2*SPLAT_IMAGE_SIZE,
>                                2*SPLAT_IMAGE_SIZE,
>                                1 );
>
> // Fix the model bounds rather than relying on vtkFastSplatter to
> calculate them
> splatter->SetModelBounds(0, 199, 0, 199, 0, 0);
> splatter->SetInputData(1, SplatImage );
>
> // The image viewers and writers are only happy with unsigned char
> // images.  This will convert the floats into that format.
> VTK_CREATE(vtkImageShiftScale, resultScale);
> resultScale->SetOutputScalarTypeToUnsignedChar();
> resultScale->SetShift(0);
> resultScale->SetScale(255);
> resultScale->SetInputConnection( splatter->GetOutputPort() );
>
> splatter->Update();
> resultScale->Update();
>
> splatter->GetOutput()->Print(cout);
>
> // Set up a viewer for the image.  vtkImageViewer and
> // vtkImageViewer2 are convenient wrappers around vtkActor2D,
> // vtkImageMapper, vtkRenderer, and vtkRenderWindow.  All you need
> // to supply is the interactor and hooray, Bob's your uncle.
> VTK_CREATE(vtkImageViewer2, ImageViewer);
> ImageViewer->SetInputConnection( resultScale->GetOutputPort() );
> ImageViewer->SetColorLevel(127);
> ImageViewer->SetColorWindow(255);
>
> VTK_CREATE(vtkRenderWindowInteractor, iren);
> ImageViewer->SetupInteractor(iren);
>
> ImageViewer->Render();
> ImageViewer->GetRenderer()->ResetCamera();
>
> iren->Initialize();
> ImageViewer->Render();
> iren->Start();
>
> return EXIT_SUCCESS;
> }
>
> HTH,
> Cory
>
>
> On Thu, Dec 17, 2015 at 6:58 AM, mbcx9rb9 <richard.j.brown at live.co.uk>
> wrote:
>
> Hi all,
>
> I was hoping to use vtkFastSplatter so I took a look at the test. However,
> it doesn't work how I expected (or how it should, I think).
>
> The example places 5 splatters at various coordinates. But I can't control
> the position of those splats. If I comment out all but the first splat and
> then change the coordinates, it doesn't move!
>
> Below is the relevant code, can someone confirm that if they change point[0]
> and point[1], nothing happens? Then, try adding in a second splat (remember
> to change Points->SetNumberOfPoints( 1 ) to 2), changing its coordinates and
> observe that weird things start happening...
>
>
> /*
> * Copyright 2004 Sandia Corporation.
> * Under the terms of Contract DE-AC04-94AL85000, there is a non-exclusive
> * license for use of this work by or on behalf of the
> * U.S. Government. Redistribution and use in source and binary forms, with
> * or without modification, are permitted provided that this Notice and any
> * statement of authorship are reproduced on all copies.
> */
>
> // Simple test of vtkFastSplatter
>
> #include "vtkImageData.h"
> #include "vtkImageShiftScale.h"
> #include "vtkFastSplatter.h"
> #include "vtkImageViewer2.h"
> #include "vtkPoints.h"
> #include "vtkPolyData.h"
> #include "vtkRenderer.h"
> #include "vtkRenderWindow.h"
> #include "vtkRenderWindowInteractor.h"
>
> #include "vtkSmartPointer.h"
> #define VTK_CREATE(type, name) \
> vtkSmartPointer<type> name = vtkSmartPointer<type>::New()
>
> #include <math.h>
>
> const int SPLAT_IMAGE_SIZE = 100;
>
> int main(int, char *[])
> {
> // For the purposes of this example we'll build the splat image by
> // hand.
>
> VTK_CREATE(vtkImageData, SplatImage);
> SplatImage->SetDimensions(SPLAT_IMAGE_SIZE, SPLAT_IMAGE_SIZE, 1);
> SplatImage->AllocateScalars(VTK_FLOAT, 1);
>
> for (int i = 0; i < SPLAT_IMAGE_SIZE; ++i)
>   {
>   for (int j = 0; j < SPLAT_IMAGE_SIZE; ++j)
>     {
>     double xCoord = 1 - fabs(  (i - SPLAT_IMAGE_SIZE/2)
>                              / (SPLAT_IMAGE_SIZE/2.0) );
>     double yCoord = 1 - fabs(  (j - SPLAT_IMAGE_SIZE/2)
>                              / (SPLAT_IMAGE_SIZE/2.0) );
>
>     SplatImage->SetScalarComponentFromDouble(i, j, 0, 0,
>                                              xCoord * yCoord );
>     }
>   }
>
> VTK_CREATE(vtkPolyData, SplatPoints);
> VTK_CREATE(vtkPoints, Points);
>
> Points->SetNumberOfPoints( 1 );
> double point[3];
>
> point[0] = 0;
> point[1] = 0;
> point[2] = 0;
> Points->SetPoint( 0, point );
> /*
> point[0] = 1;
> point[1] = 0;
> point[2] = 0;
> Points->SetPoint( 1, point );
>
> point[0] = -1;
> point[1] = 1;
> point[2] = 0;
> Points->SetPoint( 2, point );
>
> point[0] = 1;
> point[1] = -1;
> point[2] = 0;
> Points->SetPoint( 3, point );
>
> point[0] = -1;
> point[1] = -1;
> point[2] = 0;
> Points->SetPoint( 4, point );
> */
> SplatPoints->SetPoints(Points);
>
> VTK_CREATE(vtkFastSplatter, splatter);
> splatter->SetInputData( SplatPoints );
> splatter->SetOutputDimensions( 2*SPLAT_IMAGE_SIZE,
>                                2*SPLAT_IMAGE_SIZE,
>                                1 );
> splatter->SetInputData(1, SplatImage );
>
> // The image viewers and writers are only happy with unsigned char
> // images.  This will convert the floats into that format.
> VTK_CREATE(vtkImageShiftScale, resultScale);
> resultScale->SetOutputScalarTypeToUnsignedChar();
> resultScale->SetShift(0);
> resultScale->SetScale(255);
> resultScale->SetInputConnection( splatter->GetOutputPort() );
>
> splatter->Update();
> resultScale->Update();
>
> // Set up a viewer for the image.  vtkImageViewer and
> // vtkImageViewer2 are convenient wrappers around vtkActor2D,
> // vtkImageMapper, vtkRenderer, and vtkRenderWindow.  All you need
> // to supply is the interactor and hooray, Bob's your uncle.
> VTK_CREATE(vtkImageViewer2, ImageViewer);
> ImageViewer->SetInputConnection( resultScale->GetOutputPort() );
> ImageViewer->SetColorLevel(127);
> ImageViewer->SetColorWindow(255);
>
> VTK_CREATE(vtkRenderWindowInteractor, iren);
> ImageViewer->SetupInteractor(iren);
>
> ImageViewer->Render();
> ImageViewer->GetRenderer()->ResetCamera();
>
> iren->Initialize();
> ImageViewer->Render();
> iren->Start();
>
> return EXIT_SUCCESS;
> }
>
>
>
>
> --
> View this message in context:
> http://vtk.1045678.n5.nabble.com/vtkFastSplatter-broken-tp5735566.html
> Sent from the VTK - Users mailing list archive at Nabble.com.
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>
> --
> Cory Quammen
> R&D Engineer
> Kitware, Inc.
>
>
>
>
>
> --
> Cory Quammen
> R&D Engineer
> Kitware, Inc.
>
>



-- 
Cory Quammen
R&D Engineer
Kitware, Inc.