GlyphTable
VTKExamples/Python/Visualization/GlyphTable
Code¶
GlyphTable.py
import vtk # This example uses a "glyph table" to change the shape of the 3d glyphs # according to a scalar value. # NOTE: The vtkGlyph3D filter doesn't copy over scalars to the glyphs # generated by a table like this for some reason... # The Wavelet Source is nice for generating a test vtkImageData set rt = vtk.vtkRTAnalyticSource() rt.SetWholeExtent(-2,2,-2,2,0,0) # Take the gradient of the only scalar 'RTData' to get a vector attribute grad = vtk.vtkImageGradient() grad.SetDimensionality(3) grad.SetInputConnection(rt.GetOutputPort()) # Elevation just to generate another scalar attribute that varies nicely over the data range elev = vtk.vtkElevationFilter() # Elevation values will range from 0 to 1 between the Low and High Points elev.SetLowPoint(-2,-2,0) elev.SetHighPoint(2,2,0) elev.SetInputConnection(grad.GetOutputPort()) # Create simple PolyData for glyph table cs = vtk.vtkCubeSource() cs.SetXLength(0.5) cs.SetYLength(1) cs.SetZLength(2) ss = vtk.vtkSphereSource() ss.SetRadius(0.25) cs2 = vtk.vtkConeSource() cs2.SetRadius(0.25) cs2.SetHeight(0.5) # Set up the glyph filter glyph = vtk.vtkGlyph3D() glyph.SetInputConnection(elev.GetOutputPort()) # Here is where we build the glyph table # that will be indexed into according to the IndexMode glyph.SetSource(0,cs.GetOutput()) glyph.SetSource(1,ss.GetOutput()) glyph.SetSource(2,cs2.GetOutput()) glyph.ScalingOn() glyph.SetScaleModeToScaleByScalar() glyph.SetVectorModeToUseVector() glyph.OrientOn() glyph.SetScaleFactor(1) # Overall scaling factor glyph.SetRange(0, 1) # Default is (0,1) # Tell it to index into the glyph table according to scalars glyph.SetIndexModeToScalar() # Tell glyph which attribute arrays to use for what glyph.SetInputArrayToProcess(0,0,0,0,'Elevation') # scalars glyph.SetInputArrayToProcess(1,0,0,0,'RTDataGradient') # vectors # I would call Update if I could use the scalar range to set the color map range # glyph.Update() coloring_by = 'RTData' mapper = vtk.vtkPolyDataMapper() mapper.SetInputConnection(glyph.GetOutputPort()) mapper.SetScalarModeToUsePointFieldData() mapper.SetColorModeToMapScalars() mapper.ScalarVisibilityOn() # GetRange() call doesn't work because attributes weren't copied to glyphs # as they should have been... # mapper.SetScalarRange(glyph.GetOutputDataObject(0).GetPointData().GetArray(coloring_by).GetRange()) mapper.SelectColorArray(coloring_by) actor = vtk.vtkActor() actor.SetMapper(mapper) ren = vtk.vtkRenderer() ren.AddActor(actor) renWin = vtk.vtkRenderWindow() renWin.AddRenderer(ren) iren = vtk.vtkRenderWindowInteractor() istyle = vtk.vtkInteractorStyleTrackballCamera() iren.SetInteractorStyle(istyle) iren.SetRenderWindow(renWin) ren.ResetCamera() renWin.Render() iren.Start()