#!/usr/bin/python # -*- coding:Utf-8 -*- #---------------------------------------------------------------------------------------------------- # Visualization Final Project : Vector Field analysis # # Author : Arthur COSTE # Creation Date : November 30th, 2012 # Update Date : # Version : 1 # Status : Working # # Purpose : Visulalization and rendering of test vector field 1 # # # call : vtkpython vector_field_chal_1.py data_assignment3/ChalVec1.vtk data_assignment3/ChalMag1.vtk # #---------------------------------------------------------------------------------------------------- import vtk import sys chosen_pt = 2 nb_pts = 3 critical_pts = [21.3,30,20,45,45,20,65,45,20,35,15.1,20.1,55,15.2,20,7,30,15] offset = 25 print critical_pts # read input vtk file reader = vtk.vtkStructuredPointsReader() reader.SetFileName(sys.argv[1]) reader.Update() Magreader = vtk.vtkStructuredPointsReader() Magreader.SetFileName(sys.argv[2]) Magreader.Update() lutLand = vtk.vtkLookupTable() lutLand.SetNumberOfColors(256) lutLand.SetHueRange(0.65, 0.5) lutLand.SetSaturationRange(0.3, 0.0) lutLand.SetValueRange(0.75, 1.0) lutLand.Build() lut_2 = vtk.vtkLookupTable() lut_2.SetNumberOfColors(256) lut_2.SetHueRange(0.45, 0.3) lut_2.SetSaturationRange(0.7, 0.9) lut_2.SetValueRange(0.75, 1.0) lut_2.Build() lut_3 = vtk.vtkLookupTable() lut_3.SetNumberOfColors(256) lut_3.SetHueRange(0.35, 0.2) lut_3.SetSaturationRange(0.4, 0.6) lut_3.SetValueRange(0.75, 1.0) lut_3.Build() lut_4 = vtk.vtkLookupTable() lut_4.SetNumberOfColors(256) lut_4.SetHueRange(0.1, 0.2) lut_4.SetSaturationRange(0.3, 0.5) lut_4.SetValueRange(0.75, 1.0) lut_4.Build() lut_5 = vtk.vtkLookupTable() lut_5.SetNumberOfColors(256) lut_5.SetHueRange(0.1, 0.2) lut_5.SetSaturationRange(0.7, 0.8) lut_5.SetValueRange(0.75, 1.0) lut_5.Build() lut_6 = vtk.vtkLookupTable() lut_6.SetNumberOfColors(256) lut_6.SetHueRange(0.6, 0.7) lut_6.SetSaturationRange(0.1, 0.8) lut_6.SetValueRange(0.75, 1.0) lut_6.Build() lutArrow = vtk.vtkLookupTable() lutArrow.SetNumberOfColors(256) lutArrow.SetHueRange(0.0, 0.1) lutArrow.SetSaturationRange(0.5, 1.0) lutArrow.SetValueRange(0.65, 1.0) lutArrow.SetAlphaRange(0.95, 0.95) lutArrow.Build() lutSurf = vtk.vtkLookupTable() lutSurf.SetHueRange(1.0, 1.0) lutSurf.SetSaturationRange(1.0, 1.0) lutSurf.SetValueRange(1.0, 1.0) lutSurf.SetAlphaRange(0.6, 0.6) lutSurf.Build() cubeOutline = vtk.vtkOutlineFilter() cubeOutline.SetInput(reader.GetOutput()) cubeMapper = vtk.vtkPolyDataMapper() cubeMapper.SetInputConnection(cubeOutline.GetOutputPort()) cubeActor = vtk.vtkActor() cubeActor.SetMapper(cubeMapper) cubeActor.GetProperty().SetColor(1.0,1.0,1.0) arrow = vtk.vtkArrowSource() arrow.SetTipRadius(0.2) arrow.SetShaftRadius(0.075) arrow.SetTipResolution (18) arrow.SetTipLength(.4) arrowGlyph = vtk.vtkGlyph3D() arrowGlyph.SetInputConnection(reader.GetOutputPort()) arrowGlyph.SetSource(arrow.GetOutput()) arrowGlyph.SetScaleFactor(0.10) arrowGlyph.SetColorModeToColorByScalar() arrowMapper = vtk.vtkPolyDataMapper() arrowMapper.SetInputConnection(arrowGlyph.GetOutputPort()) arrowActor = vtk.vtkActor() arrowActor.SetMapper(arrowMapper) arrowActor.GetProperty().BackfaceCullingOn() integ=vtk.vtkRungeKutta45() chosen_pt = 0 point_source=vtk.vtkPointSource() point_source.SetRadius(6) point_source.SetCenter (critical_pts[(chosen_pt)*3+0],critical_pts[(chosen_pt)*3+1],critical_pts[(chosen_pt)*3+2]) point_source.SetNumberOfPoints (50) chosen_pt = 1 point_source_2=vtk.vtkPointSource() point_source_2.SetRadius(6) point_source_2.SetCenter (critical_pts[(chosen_pt)*3+0],critical_pts[(chosen_pt)*3+1],critical_pts[(chosen_pt)*3+2]) point_source_2.SetNumberOfPoints (50) chosen_pt = 2 point_source_3=vtk.vtkPointSource() point_source_3.SetRadius(6) point_source_3.SetCenter (critical_pts[(chosen_pt)*3+0],critical_pts[(chosen_pt)*3+1],critical_pts[(chosen_pt)*3+2]) point_source_3.SetNumberOfPoints (50) chosen_pt = 3 point_source_4=vtk.vtkPointSource() point_source_4.SetRadius(6) point_source_4.SetCenter (critical_pts[(chosen_pt)*3+0],critical_pts[(chosen_pt)*3+1],critical_pts[(chosen_pt)*3+2]) point_source_4.SetNumberOfPoints (50) chosen_pt = 4 point_source_5=vtk.vtkPointSource() point_source_5.SetRadius(6) point_source_5.SetCenter (critical_pts[(chosen_pt)*3+0],critical_pts[(chosen_pt)*3+1],critical_pts[(chosen_pt)*3+2]) point_source_5.SetNumberOfPoints (50) chosen_pt = 5 point_source_6=vtk.vtkPointSource() point_source_6.SetRadius(6) point_source_6.SetCenter (critical_pts[(chosen_pt)*3+0],critical_pts[(chosen_pt)*3+1],critical_pts[(chosen_pt)*3+2]) point_source_6.SetNumberOfPoints (50) extract = vtk.vtkExtractVOI() extract.SetInputConnection(reader.GetOutputPort()) extract.SetVOI(critical_pts[(chosen_pt)*3+0]-offset,critical_pts[(chosen_pt)*3+0]+offset,critical_pts[(chosen_pt)*3+1]-offset,critical_pts[(chosen_pt)*3+1]+offset,critical_pts[(chosen_pt)*3+2]-offset,critical_pts[(chosen_pt)*3+2]+offset) streamers = vtk.vtkStreamLine() streamers.SetIntegrator(integ) streamers.SetInputConnection(reader.GetOutputPort()) streamers.SetSource(point_source.GetOutput()) #streamers.SetIntegrationDirectionToForward() streamers.SetMaximumPropagationTime(8) streamers.SetStepLength(0.8) #smoothness streamers.SetIntegrationStepLength(0.1) streamers.SpeedScalarsOn() streamers.SetTerminalSpeed(0.01) streamers.SetIntegrationDirectionToIntegrateBothDirections() Magextract = vtk.vtkExtractVOI() Magextract.SetInputConnection(Magreader.GetOutputPort()) Magextract.SetVOI(critical_pts[(chosen_pt)*3+0]-offset,critical_pts[(chosen_pt)*3+0]+offset,critical_pts[(chosen_pt)*3+1]-offset,critical_pts[(chosen_pt)*3+1]+offset,critical_pts[(chosen_pt)*3+2]-offset,critical_pts[(chosen_pt)*3+2]+offset) streamers_2 = vtk.vtkStreamLine() streamers_2.SetIntegrator(integ) streamers_2.SetInputConnection(reader.GetOutputPort()) streamers_2.SetSource(point_source_2.GetOutput()) streamers_2.SetMaximumPropagationTime(8) #streamers2.SetIntegrationDirectionToForward() streamers_2.SetStepLength(0.8) #smoothness streamers_2.SetIntegrationStepLength(0.2) streamers_2.SpeedScalarsOn() streamers_2.SetTerminalSpeed(0.01) streamers_2.SetIntegrationDirectionToIntegrateBothDirections() streamers_3 = vtk.vtkStreamLine() streamers_3.SetIntegrator(integ) streamers_3.SetInputConnection(reader.GetOutputPort()) streamers_3.SetSource(point_source_3.GetOutput()) streamers_3.SetMaximumPropagationTime(8) #streamers2.SetIntegrationDirectionToForward() streamers_3.SetStepLength(0.8) #smoothness streamers_3.SetIntegrationStepLength(0.2) streamers_3.SpeedScalarsOn() streamers_3.SetTerminalSpeed(0.01) streamers_3.SetIntegrationDirectionToIntegrateBothDirections() streamers_4 = vtk.vtkStreamLine() streamers_4.SetIntegrator(integ) streamers_4.SetInputConnection(reader.GetOutputPort()) streamers_4.SetSource(point_source_4.GetOutput()) streamers_4.SetMaximumPropagationTime(8) #streamers2.SetIntegrationDirectionToForward() streamers_4.SetStepLength(0.8) #smoothness streamers_4.SetIntegrationStepLength(0.2) streamers_4.SpeedScalarsOn() streamers_4.SetTerminalSpeed(0.01) streamers_4.SetIntegrationDirectionToIntegrateBothDirections() streamers_5 = vtk.vtkStreamLine() streamers_5.SetIntegrator(integ) streamers_5.SetInputConnection(reader.GetOutputPort()) streamers_5.SetSource(point_source_5.GetOutput()) streamers_5.SetMaximumPropagationTime(8) #streamers2.SetIntegrationDirectionToForward() streamers_5.SetStepLength(0.8) #smoothness streamers_5.SetIntegrationStepLength(0.2) streamers_5.SpeedScalarsOn() streamers_5.SetTerminalSpeed(0.01) streamers_5.SetIntegrationDirectionToIntegrateBothDirections() streamers_6 = vtk.vtkStreamLine() streamers_6.SetIntegrator(integ) streamers_6.SetInputConnection(reader.GetOutputPort()) streamers_6.SetSource(point_source_6.GetOutput()) streamers_6.SetMaximumPropagationTime(8) #streamers2.SetIntegrationDirectionToForward() streamers_6.SetStepLength(0.8) #smoothness streamers_6.SetIntegrationStepLength(0.2) streamers_6.SpeedScalarsOn() streamers_6.SetTerminalSpeed(0.01) streamers_6.SetIntegrationDirectionToIntegrateBothDirections() a_streamers_1 = vtk.vtkStreamLine() a_streamers_1.SetIntegrator(integ) a_streamers_1.SetInputConnection(reader.GetOutputPort()) a_streamers_1.SetSource(point_source.GetOutput()) a_streamers_1.SetMaximumPropagationTime(250) #streamers2.SetIntegrationDirectionToForward() a_streamers_1.SetStepLength(4) #smoothness a_streamers_1.SetIntegrationStepLength(2) a_streamers_1.SpeedScalarsOn() a_streamers_1.SetTerminalSpeed(0.1) a_streamers_1.SetIntegrationDirectionToIntegrateBothDirections() a_streamers_2 = vtk.vtkStreamLine() a_streamers_2.SetIntegrator(integ) a_streamers_2.SetInputConnection(reader.GetOutputPort()) a_streamers_2.SetSource(point_source_2.GetOutput()) a_streamers_2.SetMaximumPropagationTime(250) #streamers2.SetIntegrationDirectionToForward() a_streamers_2.SetStepLength(4) #smoothness a_streamers_2.SetIntegrationStepLength(2) a_streamers_2.SpeedScalarsOn() a_streamers_2.SetTerminalSpeed(0.1) a_streamers_2.SetIntegrationDirectionToIntegrateBothDirections() a_streamers_3 = vtk.vtkStreamLine() a_streamers_3.SetIntegrator(integ) a_streamers_3.SetInputConnection(reader.GetOutputPort()) a_streamers_3.SetSource(point_source_3.GetOutput()) a_streamers_3.SetMaximumPropagationTime(250) #streamers2.SetIntegrationDirectionToForward() a_streamers_3.SetStepLength(4) #smoothness a_streamers_3.SetIntegrationStepLength(2) a_streamers_3.SpeedScalarsOn() a_streamers_3.SetTerminalSpeed(0.1) a_streamers_3.SetIntegrationDirectionToIntegrateBothDirections() a_streamers_4 = vtk.vtkStreamLine() a_streamers_4.SetIntegrator(integ) a_streamers_4.SetInputConnection(reader.GetOutputPort()) a_streamers_4.SetSource(point_source_4.GetOutput()) a_streamers_4.SetMaximumPropagationTime(250) #streamers2.SetIntegrationDirectionToForward() a_streamers_4.SetStepLength(4) #smoothness a_streamers_4.SetIntegrationStepLength(2) a_streamers_4.SpeedScalarsOn() a_streamers_4.SetTerminalSpeed(0.1) a_streamers_4.SetIntegrationDirectionToIntegrateBothDirections() a_streamers_5 = vtk.vtkStreamLine() a_streamers_5.SetIntegrator(integ) a_streamers_5.SetInputConnection(reader.GetOutputPort()) a_streamers_5.SetSource(point_source_5.GetOutput()) a_streamers_5.SetMaximumPropagationTime(250) #streamers2.SetIntegrationDirectionToForward() a_streamers_5.SetStepLength(2) #smoothness a_streamers_5.SetIntegrationStepLength(1) a_streamers_5.SpeedScalarsOn() a_streamers_5.SetTerminalSpeed(0.1) a_streamers_5.SetIntegrationDirectionToIntegrateBothDirections() a_streamers_6 = vtk.vtkStreamLine() a_streamers_6.SetIntegrator(integ) a_streamers_6.SetInputConnection(reader.GetOutputPort()) a_streamers_6.SetSource(point_source_6.GetOutput()) a_streamers_6.SetMaximumPropagationTime(250) #streamers2.SetIntegrationDirectionToForward() a_streamers_6.SetStepLength(2) #smoothness a_streamers_6.SetIntegrationStepLength(1) a_streamers_6.SpeedScalarsOn() a_streamers_6.SetTerminalSpeed(0.1) a_streamers_6.SetIntegrationDirectionToIntegrateBothDirections() vtkTubeFilter = vtk.vtkTubeFilter() vtkTubeFilter.SetInputConnection(streamers.GetOutputPort()) vtkTubeFilter.SetRadius(0.10) vtkTubeFilter.SetNumberOfSides(26) vtkTubeFilter.CappingOn() vtkTubeFilter_2 = vtk.vtkTubeFilter() vtkTubeFilter_2.SetInputConnection(streamers_2.GetOutputPort()) vtkTubeFilter_2.SetRadius(0.10) vtkTubeFilter_2.SetNumberOfSides(26) vtkTubeFilter_2.CappingOn() vtkTubeFilter_3 = vtk.vtkTubeFilter() vtkTubeFilter_3.SetInputConnection(streamers_3.GetOutputPort()) vtkTubeFilter_3.SetRadius(0.10) vtkTubeFilter_3.SetNumberOfSides(26) vtkTubeFilter_3.CappingOn() vtkTubeFilter_4 = vtk.vtkTubeFilter() vtkTubeFilter_4.SetInputConnection(streamers_4.GetOutputPort()) vtkTubeFilter_4.SetRadius(0.10) vtkTubeFilter_4.SetNumberOfSides(26) vtkTubeFilter_4.CappingOn() vtkTubeFilter_5 = vtk.vtkTubeFilter() vtkTubeFilter_5.SetInputConnection(streamers_5.GetOutputPort()) vtkTubeFilter_5.SetRadius(0.10) vtkTubeFilter_5.SetNumberOfSides(26) vtkTubeFilter_5.CappingOn() vtkTubeFilter_6 = vtk.vtkTubeFilter() vtkTubeFilter_6.SetInputConnection(streamers_6.GetOutputPort()) vtkTubeFilter_6.SetRadius(0.10) vtkTubeFilter_6.SetNumberOfSides(26) vtkTubeFilter_6.CappingOn() Glyph = vtk.vtkGlyph3D() Glyph.SetInputConnection(a_streamers_1.GetOutputPort()) Glyph.SetSource(arrow.GetOutput()) #Glyph.SetVectorModeToUseVector() Glyph.SetScaleFactor(0.75) Glyph.SetColorModeToColorByScalar() Glyph_2 = vtk.vtkGlyph3D() Glyph_2.SetInputConnection(a_streamers_2.GetOutputPort()) Glyph_2.SetSource(arrow.GetOutput()) #Glyph.SetVectorModeToUseVector() Glyph_2.SetScaleFactor(0.75) Glyph_2.SetColorModeToColorByScalar() Glyph_3 = vtk.vtkGlyph3D() Glyph_3.SetInputConnection(a_streamers_3.GetOutputPort()) Glyph_3.SetSource(arrow.GetOutput()) #Glyph.SetVectorModeToUseVector() Glyph_3.SetScaleFactor(0.75) Glyph_3.SetColorModeToColorByScalar() Glyph_4 = vtk.vtkGlyph3D() Glyph_4.SetInputConnection(a_streamers_4.GetOutputPort()) Glyph_4.SetSource(arrow.GetOutput()) #Glyph.SetVectorModeToUseVector() Glyph_4.SetScaleFactor(0.75) Glyph_4.SetColorModeToColorByScalar() Glyph_5 = vtk.vtkGlyph3D() Glyph_5.SetInputConnection(a_streamers_5.GetOutputPort()) Glyph_5.SetSource(arrow.GetOutput()) #Glyph.SetVectorModeToUseVector() Glyph_5.SetScaleFactor(0.75) Glyph_5.SetColorModeToColorByScalar() Glyph_6 = vtk.vtkGlyph3D() Glyph_6.SetInputConnection(a_streamers_6.GetOutputPort()) Glyph_6.SetSource(arrow.GetOutput()) #Glyph.SetVectorModeToUseVector() Glyph_6.SetScaleFactor(0.75) Glyph_6.SetColorModeToColorByScalar() GlyphMapper = vtk.vtkPolyDataMapper() GlyphMapper.SetInputConnection(Glyph.GetOutputPort()) GlyphMapper.SetLookupTable(lutLand) GlyphMapper.ScalarVisibilityOn() GlyphMapper.SetScalarRange(Magreader.GetOutput().GetScalarRange()) GlyphMapper_2 = vtk.vtkPolyDataMapper() GlyphMapper_2.SetInputConnection(Glyph_2.GetOutputPort()) GlyphMapper_2.SetLookupTable(lut_2) GlyphMapper_2.ScalarVisibilityOn() GlyphMapper_2.SetScalarRange(Magreader.GetOutput().GetScalarRange()) GlyphMapper_3 = vtk.vtkPolyDataMapper() GlyphMapper_3.SetInputConnection(Glyph_3.GetOutputPort()) GlyphMapper_3.SetLookupTable(lut_3) GlyphMapper_3.ScalarVisibilityOn() GlyphMapper_3.SetScalarRange(Magreader.GetOutput().GetScalarRange()) GlyphMapper_4 = vtk.vtkPolyDataMapper() GlyphMapper_4.SetInputConnection(Glyph_4.GetOutputPort()) GlyphMapper_4.SetLookupTable(lut_4) GlyphMapper_4.ScalarVisibilityOn() GlyphMapper_4.SetScalarRange(Magreader.GetOutput().GetScalarRange()) GlyphMapper_5 = vtk.vtkPolyDataMapper() GlyphMapper_5.SetInputConnection(Glyph_5.GetOutputPort()) GlyphMapper_5.SetLookupTable(lut_5) GlyphMapper_5.ScalarVisibilityOn() GlyphMapper_5.SetScalarRange(Magreader.GetOutput().GetScalarRange()) GlyphMapper_6 = vtk.vtkPolyDataMapper() GlyphMapper_6.SetInputConnection(Glyph_6.GetOutputPort()) GlyphMapper_6.SetLookupTable(lut_6) GlyphMapper_6.ScalarVisibilityOn() GlyphMapper_6.SetScalarRange(Magreader.GetOutput().GetScalarRange()) GlyphActor = vtk.vtkActor() GlyphActor.SetMapper(GlyphMapper) GlyphActor_2 = vtk.vtkActor() GlyphActor_2.SetMapper(GlyphMapper_2) GlyphActor_3 = vtk.vtkActor() GlyphActor_3.SetMapper(GlyphMapper_3) GlyphActor_4 = vtk.vtkActor() GlyphActor_4.SetMapper(GlyphMapper_4) GlyphActor_5 = vtk.vtkActor() GlyphActor_5.SetMapper(GlyphMapper_5) GlyphActor_6 = vtk.vtkActor() GlyphActor_6.SetMapper(GlyphMapper_6) streamMapper = vtk.vtkPolyDataMapper() streamMapper.SetInputConnection(vtkTubeFilter.GetOutputPort()) streamMapper.SetScalarRange(Magreader.GetOutput().GetScalarRange()) streamMapper.SetLookupTable(lutLand) streamMapper_2 = vtk.vtkPolyDataMapper() streamMapper_2.SetInputConnection(vtkTubeFilter_2.GetOutputPort()) streamMapper_2.SetScalarRange(Magreader.GetOutput().GetScalarRange()) streamMapper_2.SetLookupTable(lut_2) streamMapper_3 = vtk.vtkPolyDataMapper() streamMapper_3.SetInputConnection(vtkTubeFilter_3.GetOutputPort()) streamMapper_3.SetScalarRange(Magreader.GetOutput().GetScalarRange()) streamMapper_3.SetLookupTable(lut_3) streamMapper_4 = vtk.vtkPolyDataMapper() streamMapper_4.SetInputConnection(vtkTubeFilter_4.GetOutputPort()) streamMapper_4.SetScalarRange(Magreader.GetOutput().GetScalarRange()) streamMapper_4.SetLookupTable(lut_4) streamMapper_5 = vtk.vtkPolyDataMapper() streamMapper_5.SetInputConnection(vtkTubeFilter_5.GetOutputPort()) streamMapper_5.SetScalarRange(Magreader.GetOutput().GetScalarRange()) streamMapper_5.SetLookupTable(lut_5) streamMapper_6 = vtk.vtkPolyDataMapper() streamMapper_6.SetInputConnection(vtkTubeFilter_6.GetOutputPort()) streamMapper_6.SetScalarRange(Magreader.GetOutput().GetScalarRange()) streamMapper_6.SetLookupTable(lut_6) streamActor = vtk.vtkActor() streamActor.SetMapper(streamMapper) streamActor_2 = vtk.vtkActor() streamActor_2.SetMapper(streamMapper_2) streamActor_3 = vtk.vtkActor() streamActor_3.SetMapper(streamMapper_3) streamActor_4 = vtk.vtkActor() streamActor_4.SetMapper(streamMapper_4) streamActor_5 = vtk.vtkActor() streamActor_5.SetMapper(streamMapper_5) streamActor_6 = vtk.vtkActor() streamActor_6.SetMapper(streamMapper_6) contours = vtk.vtkContourFilter() contours.SetInputConnection(Magreader.GetOutputPort()) contours.GenerateValues(4, 0.05,1.4) contours.SetComputeNormals(1) contMapper = vtk.vtkPolyDataMapper() contMapper.SetInputConnection(contours.GetOutputPort()) contMapper.SetScalarRange(lutLand.GetTableRange()) contMapper.SetLookupTable(lutSurf) contActor = vtk.vtkActor() contActor.SetMapper(contMapper) contActor.GetProperty().SetDiffuseColor (1.0, 1.0, 1.0) contActor.GetProperty().SetSpecular(1.0) contActor.GetProperty().SetSpecularPower(8) #contActor.GetProperty().SetOpacity (0.95) #Create the renderer, render window, and interactor. ren = vtk.vtkRenderer() renWin = vtk.vtkRenderWindow() renWin.AddRenderer(ren) iren = vtk.vtkRenderWindowInteractor() iren.SetRenderWindow(renWin) # Set the background color to white. Associate the actors with the # renderer. ren.SetBackground(0, 0, 0) ren.AddActor(GlyphActor) ren.AddActor(GlyphActor_2) ren.AddActor(GlyphActor_3) ren.AddActor(GlyphActor_4) ren.AddActor(GlyphActor_5) ren.AddActor(GlyphActor_6) ren.AddActor(cubeActor) ren.AddActor(streamActor) ren.AddActor(streamActor_2) ren.AddActor(streamActor_3) ren.AddActor(streamActor_4) ren.AddActor(streamActor_5) ren.AddActor(streamActor_6) ren.AddActor(contActor) renWin.SetSize(600, 600) # Zoom in a little bit. ren.ResetCamera() ren.GetActiveCamera().Zoom(1.5) #Initialize and start the event loop. iren.Initialize() renWin.Render() iren.Start()