vv/vvSlicerManagerCommand.cxx

   1 /*=========================================================================
   2   Program:   vv                     http://www.creatis.insa-lyon.fr/rio/vv
   3
   4   Authors belong to:
   5   - University of LYON              http://www.universite-lyon.fr/
   6   - Léon Bérard cancer center       http://oncora1.lyon.fnclcc.fr
   7   - CREATIS CNRS laboratory         http://www.creatis.insa-lyon.fr
   8
   9   This software is distributed WITHOUT ANY WARRANTY; without even
  10   the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  11   PURPOSE.  See the copyright notices for more information.
  12
  13   It is distributed under dual licence
  14
  15   - BSD        See included LICENSE.txt file
  16   - CeCILL-B   http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.html
  17 ======================================================================-====*/
  18 #include "vvSlicerManagerCommand.h"
  19 #include "vvSlicerManager.h"
  20
  21 #include <vtkTextProperty.h>
  22 #include <vtkRenderer.h>
  23 #include <vtkImageActor.h>
  24 #include <vtkRenderWindowInteractor.h>
  25 #include <vtkPropPicker.h>
  26 #include <vtkCamera.h>
  27 #include <vtkImageMapToWindowLevelColors.h>
  28 #include <vtkLookupTable.h>
  29 #include <vtkMath.h>
  30 #include <vtkAbstractPropPicker.h>
  31 #include <vtkAssemblyPath.h>
  32 #include <vtkCornerAnnotation.h>
  33 #include <vtkRenderWindow.h>
  34 #include <vvImage.h>
  35 #include <vtkImageReslice.h>
  36 #include "vvSlicer.h"
  37 #include "vvInteractorStyleNavigator.h"
  38 #include "vtkTransform.h"
  39
  40 #include <cmath>
  41
  42 //------------------------------------------------------------------------------
  43 vvSlicerManagerCommand::vvSlicerManagerCommand()
  44 {
  45   mStartSlicer = -1;
  46   mSlicerNumber=-1;
  47 }
  48 //------------------------------------------------------------------------------
  49
  50
  51 //------------------------------------------------------------------------------
  52 //return the num of the current slicer if visible (-1 else)
  53 int vvSlicerManagerCommand::FindSlicerNumber(vtkRenderWindow* renwin)
  54 {
  55   int rvalue;
  56   if (renwin != SM->GetSlicer(mSlicerNumber)->GetRenderWindow() ||
  57       !SM->GetSlicer(mSlicerNumber)->GetRenderer()->GetDraw())
  58     rvalue = -1;
  59   else rvalue = mSlicerNumber;
  60   //std::cerr << this << ":" << mSlicerNumber << ": " << rvalue << endl;
  61   return rvalue;
  62 }
  63 //------------------------------------------------------------------------------
  64
  65
  66 //------------------------------------------------------------------------------
  67 void vvSlicerManagerCommand::Execute(vtkObject *caller,
  68                                      unsigned long event,
  69                                      void *vtkNotUsed(callData))
  70 {
  71   //KeyPress event
  72   vvInteractorStyleNavigator *isi =
  73     dynamic_cast<vvInteractorStyleNavigator *>(caller);
  74   if (isi) {
  75     double x = isi->GetInteractor()->GetEventPosition()[0];
  76     double y = isi->GetInteractor()->GetEventPosition()[1];
  77     double z;
  78
  79     int VisibleInWindow = this->FindSlicerNumber(isi->GetInteractor()->GetRenderWindow());
  80     vtkRenderer* renderer=NULL;
  81     if (VisibleInWindow>-1)
  82       renderer=this->SM->GetSlicer(VisibleInWindow)->GetRenderer();
  83     newLandmark = false;
  84
  85
  86
  87     if (event == vtkCommand::StartPickEvent && VisibleInWindow == -1) {
  88       for (int i = 0; i < this->SM->NumberOfSlicers(); i++) {
  89         if (this->SM->GetSlicer(i)->GetCursorVisibility()) {
  90           this->SM->GetSlicer(i)->SetCursorVisibility(0);
  91           this->SM->GetSlicer(i)->Render();
  92         }
  93       }
  94     }
  95     if ( VisibleInWindow > -1 ) {
  96       if (event == vtkCommand::KeyPressEvent) {
  97         std::string KeyPress = isi->GetInteractor()->GetKeySym();
  98         if (KeyPress == "Tab") {
  99           if(isi->GetInteractor()->GetShiftKey())
 100             this->SM->PrevImage(VisibleInWindow);
 101           else
 102             this->SM->NextImage(VisibleInWindow);
 103           return;
 104         }
 105         if (KeyPress == "f" || KeyPress == "F") {
 106           FlyToPosition(isi->GetInteractor(),this->SM->GetSlicer(VisibleInWindow));
 107           return;
 108         }
 109         if (KeyPress == "w") {
 110           this->SM->SetLocalColorWindowing(VisibleInWindow);
 111           return;
 112         }
 113         if (KeyPress == "0") {
 114           this->SM->SetPreset(0);
 115           this->SM->UpdateWindowLevel();
 116           return;
 117         }
 118         if (KeyPress == "1") {
 119           this->SM->SetPreset(1);
 120           this->SM->UpdateWindowLevel();
 121           return;
 122         }
 123         if (KeyPress == "2") {
 124           this->SM->SetPreset(2);
 125           this->SM->UpdateWindowLevel();
 126
 127           return;
 128         }
 129         if (KeyPress == "3") {
 130           this->SM->SetPreset(3);
 131           this->SM->UpdateWindowLevel();
 132           return;
 133         }
 134         if (KeyPress == "4") {
 135           this->SM->SetPreset(4);
 136           this->SM->UpdateWindowLevel();
 137           return;
 138         }
 139         if (KeyPress == "5") {
 140           this->SM->SetPreset(5);
 141           this->SM->UpdateWindowLevel();
 142           return;
 143         }
 144         if (KeyPress == "6") {
 145           this->SM->SetColorMap(0);
 146           this->SM->UpdateWindowLevel();
 147           return;
 148         }
 149         if (KeyPress == "7") {
 150           this->SM->SetColorMap(1);
 151           this->SM->UpdateWindowLevel();
 152           return;
 153         }
 154         if (KeyPress == "8") {
 155           this->SM->SetColorMap(2);
 156           this->SM->UpdateWindowLevel();
 157           return;
 158         }
 159         if (KeyPress == "9") {
 160           this->SM->SetColorMap(3);
 161           this->SM->UpdateWindowLevel();
 162           return;
 163         }
 164         if (KeyPress == "equal") { //keycodes are in vtkWin32RenderWindowInteractor
 165           this->SM->SetPreset(7);
 166           //this->SM->SetColorMap(1);
 167           this->SM->UpdateWindowLevel();
 168           return;
 169         }
 170         if (KeyPress == "minus") {
 171           this->SM->SetColorWindow(-this->SM->GetColorWindow());
 172           this->SM->SetColorMap(-1);
 173           this->SM->UpdateWindowLevel();
 174           return;
 175         }
 176         if (KeyPress == "c") {
 177           this->SM->ToggleContourSuperposition();
 178           this->SM->Render();
 179           return;
 180         }
 181         if (KeyPress == "l") {
 182           this->SM->ToggleInterpolation();
 183           this->SM->Render();
 184           return;
 185         }
 186         if (KeyPress == "h") {
 187           this->SM->SetCursorVisibility(0);
 188           this->SM->Render();
 189           return;
 190         }
 191         if (KeyPress == "x") {
 192           for(int i=0; i<SM->NumberOfSlicers(); i++) {
 193             SM->RemoveActor("overlay",0);
 194             SM->SetColorMap(0);
 195             SM->Render();
 196           }
 197           return;
 198         }
 199         if (KeyPress == "u") {
 200           this->SM->Reload();
 201           this->SM->Render();
 202           return;
 203         }
 204         if (KeyPress == "r" || KeyPress=="R") {
 205           this->SM->GetSlicer(VisibleInWindow)->ResetCamera();
 206           this->SM->GetSlicer(VisibleInWindow)->Render();
 207           return;
 208         }
 209         if (KeyPress == "g") {
 210           double* cursorPos = this->SM->GetSlicer(VisibleInWindow)->GetCursorPosition();
 211           this->SM->GetSlicer(VisibleInWindow)->SetCurrentPosition(
 212             cursorPos[0],cursorPos[1],cursorPos[2],cursorPos[3]);
 213           this->SM->UpdateViews(1,VisibleInWindow);
 214           this->SM->UpdateLinked(VisibleInWindow);
 215           return;
 216         }
 217         if (KeyPress == "F5") {
 218           this->SM->GetSlicer(VisibleInWindow)->FlipHorizontalView();
 219           this->SM->GetSlicer(VisibleInWindow)->Render();
 220           return;
 221         }
 222         if (KeyPress == "F6") {
 223           this->SM->GetSlicer(VisibleInWindow)->FlipVerticalView();
 224           this->SM->GetSlicer(VisibleInWindow)->Render();
 225           return;
 226         }
 227         if (KeyPress == "Up") {
 228           DD("------------ up");
 229           this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()+1);
 230           DD("------------ after set slice");
 231           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 232           DD("------------ after UpdateInfoOnCursorPosition");
 233           this->SM->UpdateSlice(VisibleInWindow);
 234           DD("------------ after updateslice");
 235         }
 236         if (KeyPress == "Down") {
 237           this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()-1);
 238           this->SM->UpdateSlice(VisibleInWindow);
 239           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 240         }
 241         if (KeyPress == "space") {
 242           newLandmark = true;
 243         }
 244         if (KeyPress == "Left")
 245           this->SM->SetPreviousTSlice(VisibleInWindow);
 246         if (KeyPress == "Right")
 247           this->SM->SetNextTSlice(VisibleInWindow);
 248
 249         if (KeyPress == "F2") {
 250           this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->SetText(2,"Sagital\n<slice>");
 251           this->SM->GetSlicer(VisibleInWindow)->SetSliceOrientation(0);
 252           this->SM->UpdateSliceRange(VisibleInWindow);
 253           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 254         }
 255         if (KeyPress == "F3") {
 256           this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->SetText(2,"Coronal\n<slice>");
 257           this->SM->GetSlicer(VisibleInWindow)->SetSliceOrientation(1);
 258           this->SM->UpdateSliceRange(VisibleInWindow);
 259           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 260         }
 261         if (KeyPress == "F4") {
 262           this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->SetText(2,"Axial\n<slice>");
 263           this->SM->GetSlicer(VisibleInWindow)->SetSliceOrientation(2);
 264           this->SM->UpdateSliceRange(VisibleInWindow);
 265           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 266         }
 267
 268       }
 269
 270       //All type of mouse events
 271       if (event == vtkCommand::LeaveEvent) {
 272         this->SM->GetSlicer(VisibleInWindow)->SetCurrentPosition(-VTK_DOUBLE_MAX,-VTK_DOUBLE_MAX,
 273             -VTK_DOUBLE_MAX,this->SM->GetSlicer(VisibleInWindow)->GetTSlice());
 274         this->SM->GetSlicer(VisibleInWindow)->Render();
 275         return;
 276       }
 277
 278       //DD(event);
 279       // Mouse release HERE
 280       if (event == vtkCommand::EndPickEvent) {
 281         //            DD(VisibleInWindow);
 282         if (VisibleInWindow > -1)
 283           this->SM->LeftButtonReleaseEvent(VisibleInWindow);
 284         return; // no return !!!! ???
 285       }
 286
 287       if (event == vtkCommand::StartWindowLevelEvent) {
 288         mStartSlicer = -1;
 289         this->InitialWindow = this->SM->GetColorWindow();
 290         this->InitialLevel = this->SM->GetColorLevel();
 291
 292         if (VisibleInWindow > -1) {
 293           mStartSlicer = VisibleInWindow;
 294         }
 295         return;
 296       }
 297
 298       if (event == vtkCommand::EndWindowLevelEvent) {
 299         mStartSlicer = -1;
 300       }
 301
 302       if (event == vtkCommand::EndInteractionEvent) {
 303         this->SM->UpdateLinkedNavigation(this->SM->GetSlicer(VisibleInWindow),true);
 304         return;
 305       }
 306     }
 307     if (VisibleInWindow > -1) {
 308       this->SM->Activated();
 309       //if(!this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->GetVisibility())
 310       this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->SetVisibility(1);
 311
 312       if (event == vtkCommand::MouseWheelForwardEvent && !isi->GetInteractor()->GetControlKey()) {
 313         this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()+1);
 314         this->SM->UpdateSlice(VisibleInWindow);
 315         this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 316       } else if (event == vtkCommand::MouseWheelForwardEvent && isi->GetInteractor()->GetControlKey()) {
 317         double factor = 2;
 318         this->Dolly(pow((double)1.1, factor),isi->GetInteractor());
 319       } else if (event == vtkCommand::MouseWheelBackwardEvent && !isi->GetInteractor()->GetControlKey()) {
 320         this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()-1);
 321         this->SM->UpdateSlice(VisibleInWindow);
 322         this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 323       } else if (event == vtkCommand::MouseWheelBackwardEvent && isi->GetInteractor()->GetControlKey()) {
 324         double factor = -2;
 325         this->Dolly(pow((double)1.1, factor),isi->GetInteractor());
 326       }
 327       double xWorld=0;
 328       double yWorld=0;
 329       double zWorld=0;
 330
 331       //Move into World Coordinate
 332       renderer->DisplayToNormalizedDisplay(x,y);
 333       renderer->NormalizedDisplayToViewport(x,y);
 334       renderer->ViewportToNormalizedViewport(x,y);
 335       renderer->NormalizedViewportToView(x,y,z);
 336       renderer->ViewToWorld(x,y,z);
 337       switch (this->SM->GetSlicer(VisibleInWindow)->GetSliceOrientation()) {
 338       case vtkImageViewer2::SLICE_ORIENTATION_XY:
 339         xWorld = x;
 340         yWorld = y;
 341         zWorld = this->SM->GetSlicer(VisibleInWindow)->GetSlice()*
 342                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetSpacing()[2] +
 343                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetOrigin()[2];
 344         break;
 345
 346       case vtkImageViewer2::SLICE_ORIENTATION_XZ:
 347         xWorld = x;
 348         yWorld = this->SM->GetSlicer(VisibleInWindow)->GetSlice()*
 349                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetSpacing()[1] +
 350                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetOrigin()[1];
 351         zWorld = z;
 352         break;
 353
 354       case vtkImageViewer2::SLICE_ORIENTATION_YZ:
 355         xWorld = this->SM->GetSlicer(VisibleInWindow)->GetSlice()*
 356                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetSpacing()[0] +
 357                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetOrigin()[0];
 358         yWorld = y;
 359         zWorld = z;
 360         break;
 361       }
 362       this->SM->GetSlicer(VisibleInWindow)->SetCurrentPosition(xWorld,yWorld,zWorld,
 363           this->SM->GetSlicer(VisibleInWindow)->GetTSlice());
 364       if (newLandmark) {
 365         this->SM->AddLandmark(xWorld,yWorld,zWorld,
 366                               this->SM->GetSlicer(VisibleInWindow)->GetTSlice());
 367         this->SM->GetSlicer(VisibleInWindow)->UpdateLandmarks();
 368         this->SM->Render();
 369       }
 370       if (event == vtkCommand::PickEvent || event == vtkCommand::StartPickEvent) {
 371         this->SM->UpdateViews(1,VisibleInWindow);
 372         this->SM->UpdateLinked(VisibleInWindow);
 373         this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 374       } else {
 375         this->SM->GetSlicer(VisibleInWindow)->Render();
 376       }
 377       //this->SM->GetSlicer(VisibleInWindow)->SetCurrentPosition(-VTK_DOUBLE_MAX,-VTK_DOUBLE_MAX,
 378       //-VTK_DOUBLE_MAX,this->SM->GetSlicer(VisibleInWindow)->GetTSlice());
 379       //this->SM->GetSlicer(VisibleInWindow)->Render();
 380     }
 381
 382     if (event == vtkCommand::WindowLevelEvent && mStartSlicer > -1) {
 383       this->SM->GetSlicer(mStartSlicer)->GetAnnotation()->SetVisibility(1);
 384       // Adjust the window level here
 385       int *size = isi->GetInteractor()->GetRenderWindow()->GetSize();
 386       double window = this->InitialWindow;
 387       double level = this->InitialLevel;
 388       double range[2];
 389       this->SM->GetImage()->GetScalarRange(range);
 390
 391       // Compute normalized delta
 392       double dx = static_cast<double>(isi->GetWindowLevelCurrentPosition()[0] -
 393                                       isi->GetWindowLevelStartPosition()[0]) / size[0];
 394       double dy = static_cast<double>(isi->GetWindowLevelStartPosition()[1] -
 395                                       isi->GetWindowLevelCurrentPosition()[1]) / size[1];
 396       //Window is exponential in nature, use exponential to avoid falling into negative numbers
 397       dx = std::exp(1.0 * (dx*fabs(dx) + dx)) ; //Quadratic behavior for more reactive interface
 398       dy = 0.15 * (dy*fabs(dy) + dy) * (range[1]-range[0]);//Quadratic behavior for more reactive interface
 399
 400       this->SM->SetColorWindow(window*dx);
 401       this->SM->SetColorLevel(level-dy);
 402       this->SM->SetPreset(6);
 403       this->SM->UpdateWindowLevel();
 404       this->SM->Render();
 405       return;
 406     }
 407   }
 408 }
 409 //------------------------------------------------------------------------------
 410
 411
 412 //------------------------------------------------------------------------------
 413 void vvSlicerManagerCommand::Dolly(double factor, vtkRenderWindowInteractor *interactor)
 414 {
 415   int VisibleInWindow = this->FindSlicerNumber(interactor->GetRenderWindow());
 416   vtkRenderer* renderer;
 417   if (VisibleInWindow>-1)
 418     renderer=this->SM->GetSlicer(VisibleInWindow)->GetRenderer();
 419   else {
 420     return;
 421   }
 422
 423   double viewFocus[4],viewPoint[4],motionVector[3], focalDepth;
 424   double oldPos[3], newPos[3], distance[2];
 425   vtkCamera *camera = renderer->GetActiveCamera();
 426   camera->GetFocalPoint(viewFocus);
 427
 428   renderer->SetWorldPoint(viewFocus[0], viewFocus[0], viewFocus[0], 1.0);
 429   renderer->WorldToDisplay();
 430   renderer->GetDisplayPoint(viewFocus);
 431
 432   focalDepth = viewFocus[2];
 433
 434   oldPos[0] = renderer->GetCenter()[0];
 435   oldPos[1] = renderer->GetCenter()[1];
 436   oldPos[2] = focalDepth;
 437
 438   distance[0] = 1/factor*
 439                 (interactor->GetEventPosition()[0]-renderer->GetCenter()[0]);
 440   distance[1] = 1/factor*
 441                 (interactor->GetEventPosition()[1]-renderer->GetCenter()[1]);
 442
 443   newPos[0] = interactor->GetEventPosition()[0] - distance[0];
 444   newPos[1] = interactor->GetEventPosition()[1] - distance[1];
 445   newPos[2] = focalDepth;
 446
 447   renderer->DisplayToNormalizedDisplay(oldPos[0],oldPos[1]);
 448   renderer->NormalizedDisplayToViewport(oldPos[0],oldPos[1]);
 449   renderer->ViewportToNormalizedViewport(oldPos[0],oldPos[1]);
 450   renderer->NormalizedViewportToView(oldPos[0],oldPos[1],oldPos[2]);
 451   renderer->ViewToWorld(oldPos[0],oldPos[1],oldPos[2]);
 452
 453   renderer->DisplayToNormalizedDisplay(newPos[0],newPos[1]);
 454   renderer->NormalizedDisplayToViewport(newPos[0],newPos[1]);
 455   renderer->ViewportToNormalizedViewport(newPos[0],newPos[1]);
 456   renderer->NormalizedViewportToView(newPos[0],newPos[1],newPos[2]);
 457   renderer->ViewToWorld(newPos[0],newPos[1],newPos[2]);
 458
 459   motionVector[0] = newPos[0] - oldPos[0];
 460   motionVector[1] = newPos[1] - oldPos[1];
 461   motionVector[2] = newPos[2] - oldPos[2];
 462
 463   camera->GetFocalPoint(viewFocus);
 464   camera->GetPosition(viewPoint);
 465   camera->SetFocalPoint(motionVector[0] + viewFocus[0],
 466                         motionVector[1] + viewFocus[1],
 467                         motionVector[2] + viewFocus[2]);
 468
 469   camera->SetPosition(motionVector[0] + viewPoint[0],
 470                       motionVector[1] + viewPoint[1],
 471                       motionVector[2] + viewPoint[2]);
 472
 473   if (camera->GetParallelProjection()) {
 474     camera->SetParallelScale(camera->GetParallelScale() / factor);
 475   } else {
 476     camera->Dolly(factor);
 477   }
 478
 479   if (interactor->GetLightFollowCamera()) {
 480     renderer->UpdateLightsGeometryToFollowCamera();
 481   }
 482   renderer->ResetCameraClippingRange();
 483   //interactor->Render();
 484 }
 485 //------------------------------------------------------------------------------
 486
 487
 488 //------------------------------------------------------------------------------
 489 void vvSlicerManagerCommand::FlyToPosition(vtkRenderWindowInteractor *interactor,vvSlicer* slicer)
 490 {
 491   double flyFrom[3], flyTo[3];
 492   double d[3], focalPt[3], position[3], positionFrom[3];
 493   int i, j;
 494   int VisibleInWindow = this->FindSlicerNumber(interactor->GetRenderWindow());
 495   vtkRenderer* renderer=NULL;
 496   if (VisibleInWindow>-1)
 497     renderer=this->SM->GetSlicer(VisibleInWindow)->GetRenderer();
 498   else
 499     return;
 500
 501   interactor->GetPicker()->Pick(interactor->GetEventPosition()[0],
 502                                 interactor->GetEventPosition()[1], 0.0,
 503                                 renderer);
 504
 505   vtkAssemblyPath *path=NULL;
 506   vtkAbstractPropPicker *picker;
 507   if ( (picker=vtkAbstractPropPicker::SafeDownCast(interactor->GetPicker()))) {
 508     path = picker->GetPath();
 509   }
 510   if ( path != NULL ) {
 511     flyTo[0] = picker->GetPickPosition()[0];
 512     flyTo[1] = picker->GetPickPosition()[1];
 513     flyTo[2] = picker->GetPickPosition()[2];
 514     renderer->GetActiveCamera()->GetFocalPoint(flyFrom);
 515     renderer->GetActiveCamera()->GetPosition(positionFrom);
 516
 517     switch (slicer->GetSliceOrientation()) {
 518     case vtkImageViewer2::SLICE_ORIENTATION_XY:
 519       flyTo[2] = flyFrom[2];
 520       break;
 521
 522     case vtkImageViewer2::SLICE_ORIENTATION_XZ:
 523       flyTo[1] = flyFrom[1];
 524       break;
 525
 526     case vtkImageViewer2::SLICE_ORIENTATION_YZ:
 527       flyTo[0] = flyFrom[0];
 528       break;
 529     }
 530
 531
 532     for (i=0; i<3; i++) {
 533       d[i] = flyTo[i] - flyFrom[i];
 534     }
 535     double distance = vtkMath::Normalize(d);
 536     double delta = distance/15;
 537
 538     for (i=1; i<=15; i++) {
 539       for (j=0; j<3; j++) {
 540         focalPt[j] = flyFrom[j] + d[j]*i*delta;
 541         position[j] = positionFrom[j] + d[j]*i*delta;
 542       }
 543       renderer->GetActiveCamera()->SetFocalPoint(focalPt);
 544       renderer->GetActiveCamera()->SetPosition(position);
 545       renderer->GetActiveCamera()->Dolly(0.3/15 + 1.0);
 546       renderer->ResetCameraClippingRange();
 547       interactor->Render();
 548     }
 549   }
 550 }
 551 //------------------------------------------------------------------------------