How do I color a polydata surface of N points using an Nx3 array where the columns correspond to H,S,V values? I have tried using mapper.SetColorModeToDefault() but it doesn’t seem to do what I thought it did. I will be fine with using RGB values if necessary, I can just pre-convert my HSV values using the python colorsys module. My current code is:
#!/usr/bin/env python
# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonDataModel import vtkPolyData
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkFiltersCore import vtkElevationFilter
from vtkmodules.vtkFiltersSources import vtkSphereSource
from vtkmodules.vtkRenderingCore import (
vtkActor,
vtkDataSetMapper,
vtkRenderWindow,
vtkRenderWindowInteractor,
vtkRenderer
)
from vtk.util import numpy_support as ns
from vtk import VTK_UNSIGNED_CHAR
import numpy as np
def main():
renderer = vtkRenderer()
renWin = vtkRenderWindow()
renWin.AddRenderer(renderer)
iren = vtkRenderWindowInteractor()
iren.SetRenderWindow(renWin)
sphere = vtkSphereSource()
sphere.SetPhiResolution(12)
sphere.SetThetaResolution(12)
sphere.Update()
polydata = vtkPolyData()
polydata.ShallowCopy(sphere.GetOutput())
N = polydata.GetNumberOfPoints()
# Create N-by-3 array, where the columns should correspond to H,S and V values at each point
my_data_array = (np.random.random((N,3))*256).astype(np.uint8)
vtk_array = ns.numpy_to_vtk(num_array=my_data_array, deep=True, array_type=VTK_UNSIGNED_CHAR)
vtk_array.SetName("HSV")
polydata.GetPointData().AddArray(vtk_array)
mapper = vtkDataSetMapper()
mapper.SelectColorArray("HSV")
mapper.SetInputData(polydata);
mapper.SetColorModeToDefault()
mapper.ScalarVisibilityOff()
actor = vtkActor()
actor.SetMapper(mapper)
renderer.AddActor(actor)
renWin.SetSize(640, 480)
renWin.SetWindowName('ColoredSphere')
renWin.Render()
# Interact with the data.
iren.Start()
if __name__ == '__main__':
main()