VelocityProfile
vtk-examples/Python/VisualizationAlgorithms/VelocityProfile
Description¶
This example shows shows warped planes in a structured grid dataset. The planes are warped according to flow momentum. The relative back and forward flow are clearly visible in the deformation of the planes.
Info
See Figure 6-14b in Chapter 6 the VTK Textbook.
Other languages
See (Cxx)
Question
If you have a question about this example, please use the VTK Discourse Forum
Code¶
VelocityProfile.py
#!/usr/bin/env python
# Translated from velProf.tcl.
# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkFiltersCore import (
vtkAppendPolyData,
vtkPolyDataNormals,
vtkStructuredGridOutlineFilter
)
from vtkmodules.vtkFiltersGeneral import vtkWarpVector
from vtkmodules.vtkFiltersGeometry import vtkStructuredGridGeometryFilter
from vtkmodules.vtkIOParallel import vtkMultiBlockPLOT3DReader
from vtkmodules.vtkRenderingCore import (
vtkActor,
vtkPolyDataMapper,
vtkRenderWindow,
vtkRenderWindowInteractor,
vtkRenderer
)
def main():
fileName1, fileName2 = get_program_parameters()
colors = vtkNamedColors()
# Set the background color.
colors.SetColor('BkgColor', [65, 99, 149, 255])
# Read a vtk file
#
pl3d = vtkMultiBlockPLOT3DReader()
pl3d.SetXYZFileName(fileName1)
pl3d.SetQFileName(fileName2)
pl3d.SetScalarFunctionNumber(100) # Density
pl3d.SetVectorFunctionNumber(202) # Momentum
pl3d.Update()
pl3dOutput = pl3d.GetOutput().GetBlock(0)
# What do we know about the data?
# Get the extent of the data: imin,imax, jmin,jmax, kmin,kmax
extent = pl3dOutput.GetExtent()
scalarRange = pl3dOutput.GetScalarRange()
# Planes are specified using a imin,imax, jmin,jmax, kmin,kmax coordinate
# specification. Min and max i,j,k values are clamped to 0 and maximum value.
# See the variable named extent for the values.
#
plane = vtkStructuredGridGeometryFilter()
plane.SetInputData(pl3dOutput)
plane.SetExtent(10, 10, 1, extent[3], 1, extent[5])
plane2 = vtkStructuredGridGeometryFilter()
plane2.SetInputData(pl3dOutput)
plane2.SetExtent(30, 30, 1, extent[3], 1, extent[5])
plane3 = vtkStructuredGridGeometryFilter()
plane3.SetInputData(pl3dOutput)
plane3.SetExtent(45, 45, 1, extent[3], 1, extent[5])
# We use an append filter because that way we can do the warping, etc. just
# using a single pipeline and actor.
#
appendF = vtkAppendPolyData()
appendF.AddInputConnection(plane.GetOutputPort())
appendF.AddInputConnection(plane2.GetOutputPort())
appendF.AddInputConnection(plane3.GetOutputPort())
# Warp
warp = vtkWarpVector()
warp.SetInputConnection(appendF.GetOutputPort())
warp.SetScaleFactor(0.005)
warp.Update()
normals = vtkPolyDataNormals()
normals.SetInputData(warp.GetPolyDataOutput())
normals.SetFeatureAngle(45)
planeMapper = vtkPolyDataMapper()
planeMapper.SetInputConnection(normals.GetOutputPort())
planeMapper.SetScalarRange(scalarRange)
planeActor = vtkActor()
planeActor.SetMapper(planeMapper)
# The outline provides context for the data and the planes.
outline = vtkStructuredGridOutlineFilter()
outline.SetInputData(pl3dOutput)
outlineMapper = vtkPolyDataMapper()
outlineMapper.SetInputConnection(outline.GetOutputPort())
outlineActor = vtkActor()
outlineActor.SetMapper(outlineMapper)
outlineActor.GetProperty().SetColor(colors.GetColor3d('Black'))
# Create the RenderWindow, Renderer and both Actors
#
ren = vtkRenderer()
renWin = vtkRenderWindow()
renWin.AddRenderer(ren)
iren = vtkRenderWindowInteractor()
iren.SetRenderWindow(renWin)
# Add the actors to the renderer, set the background and size
#
ren.AddActor(planeActor)
ren.AddActor(outlineActor)
ren.SetBackground(colors.GetColor3d('BkgColor'))
renWin.SetSize(512, 512)
renWin.SetWindowName('VelocityProfile')
iren.Initialize()
renWin.Render()
ren.GetActiveCamera().SetPosition(19.8562, -31.8912, 47.0755)
ren.GetActiveCamera().SetFocalPoint(8.255, 0.147815, 29.7631)
ren.GetActiveCamera().SetViewUp(-0.0333325, 0.465756, 0.884285)
ren.GetActiveCamera().SetClippingRange(17.3078, 64.6375)
renWin.Render()
iren.Start()
def get_program_parameters():
import argparse
description = 'Produce figure 6–14(b) Flow momentum from the VTK Textbook.'
epilogue = '''
Produce figure 6–14(b) Flow momentum from the VTK Textbook.
'''
parser = argparse.ArgumentParser(description=description, epilog=epilogue)
parser.add_argument('filename1', help='combxyz.bin.')
parser.add_argument('filename2', help='combq.bin.')
args = parser.parse_args()
return args.filename1, args.filename2
if __name__ == '__main__':
main()