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           {
 194            SM->RemoveActor("overlay",0);
 195            SM->SetColorMap(0);
 196            SM->Render();
 197           }
 198            return;
 199         }
 200         if (KeyPress == "u") {
 201           this->SM->Reload();
 202           this->SM->Render();
 203           return;
 204         }
 205         if (KeyPress == "r" || KeyPress=="R") {
 206           this->SM->GetSlicer(VisibleInWindow)->ResetCamera();
 207           this->SM->GetSlicer(VisibleInWindow)->Render();
 208           return;
 209         }
 210         if (KeyPress == "g") {
 211           double* cursorPos = this->SM->GetSlicer(VisibleInWindow)->GetCursorPosition();
 212           this->SM->GetSlicer(VisibleInWindow)->SetCurrentPosition(
 213             cursorPos[0],cursorPos[1],cursorPos[2],cursorPos[3]);
 214           this->SM->UpdateViews(1,VisibleInWindow);
 215           this->SM->UpdateLinked(VisibleInWindow);
 216           return;
 217         }
 218         if (KeyPress == "F5") {
 219           this->SM->GetSlicer(VisibleInWindow)->FlipHorizontalView();
 220           this->SM->GetSlicer(VisibleInWindow)->Render();
 221           return;
 222         }
 223         if (KeyPress == "F6") {
 224           this->SM->GetSlicer(VisibleInWindow)->FlipVerticalView();
 225           this->SM->GetSlicer(VisibleInWindow)->Render();
 226           return;
 227         }
 228         if (KeyPress == "Up") {
 229           DD("------------ up");
 230           this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()+1);
 231           DD("------------ after set slice");
 232           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 233           DD("------------ after UpdateInfoOnCursorPosition");
 234           this->SM->UpdateSlice(VisibleInWindow);
 235           DD("------------ after updateslice");
 236         }
 237         if (KeyPress == "Down") {
 238           this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()-1);
 239           this->SM->UpdateSlice(VisibleInWindow);
 240           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 241         }
 242         if (KeyPress == "space") {
 243           newLandmark = true;
 244         }
 245         if (KeyPress == "Left")
 246           this->SM->SetPreviousTSlice(VisibleInWindow);
 247         if (KeyPress == "Right")
 248           this->SM->SetNextTSlice(VisibleInWindow);
 249
 250         if (KeyPress == "F2") {
 251           this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->SetText(2,"Sagital\n<slice>");
 252           this->SM->GetSlicer(VisibleInWindow)->SetSliceOrientation(0);
 253           this->SM->UpdateSliceRange(VisibleInWindow);
 254           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 255         }
 256         if (KeyPress == "F3") {
 257           this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->SetText(2,"Coronal\n<slice>");
 258           this->SM->GetSlicer(VisibleInWindow)->SetSliceOrientation(1);
 259           this->SM->UpdateSliceRange(VisibleInWindow);
 260           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 261         }
 262         if (KeyPress == "F4") {
 263           this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->SetText(2,"Axial\n<slice>");
 264           this->SM->GetSlicer(VisibleInWindow)->SetSliceOrientation(2);
 265           this->SM->UpdateSliceRange(VisibleInWindow);
 266           this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 267         }
 268
 269       }
 270
 271       //All type of mouse events
 272       if (event == vtkCommand::LeaveEvent) {
 273         this->SM->GetSlicer(VisibleInWindow)->SetCurrentPosition(-VTK_DOUBLE_MAX,-VTK_DOUBLE_MAX,
 274             -VTK_DOUBLE_MAX,this->SM->GetSlicer(VisibleInWindow)->GetTSlice());
 275         this->SM->GetSlicer(VisibleInWindow)->Render();
 276         return;
 277       }
 278
 279       //DD(event);
 280       // Mouse release HERE
 281       if (event == vtkCommand::EndPickEvent) {
 282         //            DD(VisibleInWindow);
 283         if (VisibleInWindow > -1)
 284           this->SM->LeftButtonReleaseEvent(VisibleInWindow);
 285         return; // no return !!!! ???
 286       }
 287
 288       if (event == vtkCommand::StartWindowLevelEvent) {
 289         mStartSlicer = -1;
 290         this->InitialWindow = this->SM->GetColorWindow();
 291         this->InitialLevel = this->SM->GetColorLevel();
 292
 293         if (VisibleInWindow > -1) {
 294           mStartSlicer = VisibleInWindow;
 295         }
 296         return;
 297       }
 298
 299       if (event == vtkCommand::EndWindowLevelEvent) {
 300         mStartSlicer = -1;
 301       }
 302
 303     }
 304     if (VisibleInWindow > -1) {
 305       this->SM->Activated();
 306       //if(!this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->GetVisibility())
 307       this->SM->GetSlicer(VisibleInWindow)->GetAnnotation()->SetVisibility(1);
 308
 309       if (event == vtkCommand::MouseWheelForwardEvent && !isi->GetInteractor()->GetControlKey()) {
 310         this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()+1);
 311         this->SM->UpdateSlice(VisibleInWindow);
 312         this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 313       } else if (event == vtkCommand::MouseWheelForwardEvent && isi->GetInteractor()->GetControlKey()) {
 314         double factor = 2;
 315         this->Dolly(pow((double)1.1, factor),isi->GetInteractor());
 316       } else if (event == vtkCommand::MouseWheelBackwardEvent && !isi->GetInteractor()->GetControlKey()) {
 317         this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()-1);
 318         this->SM->UpdateSlice(VisibleInWindow);
 319         this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 320       } else if (event == vtkCommand::MouseWheelBackwardEvent && isi->GetInteractor()->GetControlKey()) {
 321         double factor = -2;
 322         this->Dolly(pow((double)1.1, factor),isi->GetInteractor());
 323       }
 324       double xWorld=0;
 325       double yWorld=0;
 326       double zWorld=0;
 327
 328       //Move into World Coordinate
 329       renderer->DisplayToNormalizedDisplay(x,y);
 330       renderer->NormalizedDisplayToViewport(x,y);
 331       renderer->ViewportToNormalizedViewport(x,y);
 332       renderer->NormalizedViewportToView(x,y,z);
 333       renderer->ViewToWorld(x,y,z);
 334       switch (this->SM->GetSlicer(VisibleInWindow)->GetSliceOrientation()) {
 335       case vtkImageViewer2::SLICE_ORIENTATION_XY:
 336         xWorld = x;
 337         yWorld = y;
 338         zWorld = this->SM->GetSlicer(VisibleInWindow)->GetSlice()*
 339                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetSpacing()[2] +
 340                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetOrigin()[2];
 341         break;
 342
 343       case vtkImageViewer2::SLICE_ORIENTATION_XZ:
 344         xWorld = x;
 345         yWorld = this->SM->GetSlicer(VisibleInWindow)->GetSlice()*
 346                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetSpacing()[1] +
 347                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetOrigin()[1];
 348         zWorld = z;
 349         break;
 350
 351       case vtkImageViewer2::SLICE_ORIENTATION_YZ:
 352         xWorld = this->SM->GetSlicer(VisibleInWindow)->GetSlice()*
 353                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetSpacing()[0] +
 354                  this->SM->GetSlicer(VisibleInWindow)->GetInput()->GetOrigin()[0];
 355         yWorld = y;
 356         zWorld = z;
 357         break;
 358       }
 359       this->SM->GetSlicer(VisibleInWindow)->SetCurrentPosition(xWorld,yWorld,zWorld,
 360           this->SM->GetSlicer(VisibleInWindow)->GetTSlice());
 361       if (newLandmark) {
 362         this->SM->AddLandmark(xWorld,yWorld,zWorld,
 363                               this->SM->GetSlicer(VisibleInWindow)->GetTSlice());
 364         this->SM->GetSlicer(VisibleInWindow)->UpdateLandmarks();
 365         this->SM->Render();
 366       }
 367       if (event == vtkCommand::PickEvent || event == vtkCommand::StartPickEvent) {
 368         this->SM->UpdateViews(1,VisibleInWindow);
 369         this->SM->UpdateLinked(VisibleInWindow);
 370         this->SM->UpdateInfoOnCursorPosition(VisibleInWindow);
 371       } else {
 372         this->SM->GetSlicer(VisibleInWindow)->Render();
 373       }
 374       //this->SM->GetSlicer(VisibleInWindow)->SetCurrentPosition(-VTK_DOUBLE_MAX,-VTK_DOUBLE_MAX,
 375       //-VTK_DOUBLE_MAX,this->SM->GetSlicer(VisibleInWindow)->GetTSlice());
 376       //this->SM->GetSlicer(VisibleInWindow)->Render();
 377     }
 378
 379     if (event == vtkCommand::WindowLevelEvent && mStartSlicer > -1) {
 380       this->SM->GetSlicer(mStartSlicer)->GetAnnotation()->SetVisibility(1);
 381       // Adjust the window level here
 382       int *size = isi->GetInteractor()->GetRenderWindow()->GetSize();
 383       double window = this->InitialWindow;
 384       double level = this->InitialLevel;
 385       double range[2];
 386       this->SM->GetImage()->GetScalarRange(range);
 387
 388       // Compute normalized delta
 389       double dx = static_cast<double>(isi->GetWindowLevelCurrentPosition()[0] -
 390                                       isi->GetWindowLevelStartPosition()[0]) / size[0];
 391       double dy = static_cast<double>(isi->GetWindowLevelStartPosition()[1] -
 392                                       isi->GetWindowLevelCurrentPosition()[1]) / size[1];
 393       //Window is exponential in nature, use exponential to avoid falling into negative numbers
 394       dx = std::exp(1.0 * (dx*fabs(dx) + dx)) ; //Quadratic behavior for more reactive interface
 395       dy = 0.15 * (dy*fabs(dy) + dy) * (range[1]-range[0]);//Quadratic behavior for more reactive interface
 396
 397       this->SM->SetColorWindow(window*dx);
 398       this->SM->SetColorLevel(level-dy);
 399       this->SM->SetPreset(6);
 400       this->SM->UpdateWindowLevel();
 401       this->SM->Render();
 402       return;
 403     }
 404   }
 405 }
 406 //------------------------------------------------------------------------------
 407
 408
 409 //------------------------------------------------------------------------------
 410 void vvSlicerManagerCommand::Dolly(double factor, vtkRenderWindowInteractor *interactor)
 411 {
 412   int VisibleInWindow = this->FindSlicerNumber(interactor->GetRenderWindow());
 413   vtkRenderer* renderer;
 414   if (VisibleInWindow>-1)
 415     renderer=this->SM->GetSlicer(VisibleInWindow)->GetRenderer();
 416   else {
 417     return;
 418   }
 419
 420   double viewFocus[4],viewPoint[4],motionVector[3], focalDepth;
 421   double oldPos[3], newPos[3], distance[2];
 422   vtkCamera *camera = renderer->GetActiveCamera();
 423   camera->GetFocalPoint(viewFocus);
 424
 425   renderer->SetWorldPoint(viewFocus[0], viewFocus[0], viewFocus[0], 1.0);
 426   renderer->WorldToDisplay();
 427   renderer->GetDisplayPoint(viewFocus);
 428
 429   focalDepth = viewFocus[2];
 430
 431   oldPos[0] = renderer->GetCenter()[0];
 432   oldPos[1] = renderer->GetCenter()[1];
 433   oldPos[2] = focalDepth;
 434
 435   distance[0] = 1/factor*
 436                 (interactor->GetEventPosition()[0]-renderer->GetCenter()[0]);
 437   distance[1] = 1/factor*
 438                 (interactor->GetEventPosition()[1]-renderer->GetCenter()[1]);
 439
 440   newPos[0] = interactor->GetEventPosition()[0] - distance[0];
 441   newPos[1] = interactor->GetEventPosition()[1] - distance[1];
 442   newPos[2] = focalDepth;
 443
 444   renderer->DisplayToNormalizedDisplay(oldPos[0],oldPos[1]);
 445   renderer->NormalizedDisplayToViewport(oldPos[0],oldPos[1]);
 446   renderer->ViewportToNormalizedViewport(oldPos[0],oldPos[1]);
 447   renderer->NormalizedViewportToView(oldPos[0],oldPos[1],oldPos[2]);
 448   renderer->ViewToWorld(oldPos[0],oldPos[1],oldPos[2]);
 449
 450   renderer->DisplayToNormalizedDisplay(newPos[0],newPos[1]);
 451   renderer->NormalizedDisplayToViewport(newPos[0],newPos[1]);
 452   renderer->ViewportToNormalizedViewport(newPos[0],newPos[1]);
 453   renderer->NormalizedViewportToView(newPos[0],newPos[1],newPos[2]);
 454   renderer->ViewToWorld(newPos[0],newPos[1],newPos[2]);
 455
 456   motionVector[0] = newPos[0] - oldPos[0];
 457   motionVector[1] = newPos[1] - oldPos[1];
 458   motionVector[2] = newPos[2] - oldPos[2];
 459
 460   camera->GetFocalPoint(viewFocus);
 461   camera->GetPosition(viewPoint);
 462   camera->SetFocalPoint(motionVector[0] + viewFocus[0],
 463                         motionVector[1] + viewFocus[1],
 464                         motionVector[2] + viewFocus[2]);
 465
 466   camera->SetPosition(motionVector[0] + viewPoint[0],
 467                       motionVector[1] + viewPoint[1],
 468                       motionVector[2] + viewPoint[2]);
 469
 470   if (camera->GetParallelProjection()) {
 471     camera->SetParallelScale(camera->GetParallelScale() / factor);
 472   } else {
 473     camera->Dolly(factor);
 474   }
 475
 476   if (interactor->GetLightFollowCamera()) {
 477     renderer->UpdateLightsGeometryToFollowCamera();
 478   }
 479   renderer->ResetCameraClippingRange();
 480   //interactor->Render();
 481 }
 482 //------------------------------------------------------------------------------
 483
 484
 485 //------------------------------------------------------------------------------
 486 void vvSlicerManagerCommand::FlyToPosition(vtkRenderWindowInteractor *interactor,vvSlicer* slicer)
 487 {
 488   double flyFrom[3], flyTo[3];
 489   double d[3], focalPt[3], position[3], positionFrom[3];
 490   int i, j;
 491   int VisibleInWindow = this->FindSlicerNumber(interactor->GetRenderWindow());
 492   vtkRenderer* renderer=NULL;
 493   if (VisibleInWindow>-1)
 494     renderer=this->SM->GetSlicer(VisibleInWindow)->GetRenderer();
 495   else
 496     return;
 497
 498   interactor->GetPicker()->Pick(interactor->GetEventPosition()[0],
 499                                 interactor->GetEventPosition()[1], 0.0,
 500                                 renderer);
 501
 502   vtkAssemblyPath *path=NULL;
 503   vtkAbstractPropPicker *picker;
 504   if ( (picker=vtkAbstractPropPicker::SafeDownCast(interactor->GetPicker()))) {
 505     path = picker->GetPath();
 506   }
 507   if ( path != NULL ) {
 508     flyTo[0] = picker->GetPickPosition()[0];
 509     flyTo[1] = picker->GetPickPosition()[1];
 510     flyTo[2] = picker->GetPickPosition()[2];
 511     renderer->GetActiveCamera()->GetFocalPoint(flyFrom);
 512     renderer->GetActiveCamera()->GetPosition(positionFrom);
 513
 514     switch (slicer->GetSliceOrientation()) {
 515     case vtkImageViewer2::SLICE_ORIENTATION_XY:
 516       flyTo[2] = flyFrom[2];
 517       break;
 518
 519     case vtkImageViewer2::SLICE_ORIENTATION_XZ:
 520       flyTo[1] = flyFrom[1];
 521       break;
 522
 523     case vtkImageViewer2::SLICE_ORIENTATION_YZ:
 524       flyTo[0] = flyFrom[0];
 525       break;
 526     }
 527
 528
 529     for (i=0; i<3; i++) {
 530       d[i] = flyTo[i] - flyFrom[i];
 531     }
 532     double distance = vtkMath::Normalize(d);
 533     double delta = distance/15;
 534
 535     for (i=1; i<=15; i++) {
 536       for (j=0; j<3; j++) {
 537         focalPt[j] = flyFrom[j] + d[j]*i*delta;
 538         position[j] = positionFrom[j] + d[j]*i*delta;
 539       }
 540       renderer->GetActiveCamera()->SetFocalPoint(focalPt);
 541       renderer->GetActiveCamera()->SetPosition(position);
 542       renderer->GetActiveCamera()->Dolly(0.3/15 + 1.0);
 543       renderer->ResetCameraClippingRange();
 544       interactor->Render();
 545     }
 546   }
 547 }
 548 //------------------------------------------------------------------------------