# How to export colors of vtk lookuptable with vtkOBJExporter

**URL:** https://discourse.vtk.org/t/how-to-export-colors-of-vtk-lookuptable-with-vtkobjexporter/11181
**Category:** Support
**Tags:** python
**Created:** [April 11, 2023, 7:18pm UTC](https://discourse.vtk.org/t/how-to-export-colors-of-vtk-lookuptable-with-vtkobjexporter/11181 "2023-04-11T19:18:01Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![Wagner\_Ramalho](https://discourse.vtk.org/user_avatar/discourse.vtk.org/wagner_ramalho/32/6865_2.png) [@Wagner\_Ramalho](https://discourse.vtk.org/u/Wagner_Ramalho)
#### Post date: [April 11, 2023, 7:18pm UTC](https://discourse.vtk.org/t/how-to-export-colors-of-vtk-lookuptable-with-vtkobjexporter/11181/1 "2023-04-11T19:18:01Z")

</div>

I was looking for a way to export colors generated by lookuptable from scalars to a mtl file and found vtkOBJExporter. The mtl receive the object with color setted by actor.GetProperty().SetColor, but dont receive colors of lookuptable. Is there a way to receive this colors and export to mtl by vtkOBJExporter or another class?

My objective is transform a big unstructuredgrid to a object to be render in vtk.js

```auto
from vtk import *

colors = vtkNamedColors()
sphere = vtkSphereSource()
sphere.SetCenter(0, 0, 0)
sphere.SetRadius(1)
sphere.Update()

numPts = sphere.GetOutput().GetPoints().GetNumberOfPoints()
print(sphere.GetOutput().GetPoints())
scalars = vtkFloatArray()
scalars.SetNumberOfValues(numPts)
scalars.SetValue(1, 0.2)
for i in range(0, numPts):
    scalars.SetValue(i, i /numPts)
poly = vtkPolyData()
poly.DeepCopy(sphere.GetOutput())
poly.GetPointData().SetScalars(scalars)
mapper = vtkPolyDataMapper()
mapper.SetInputData(poly)
mapper.ScalarVisibilityOn()
mapper.SetScalarModeToUsePointData()
mapper.SetColorModeToMapScalars()

actor = vtkActor()
actor.GetProperty().SetColor(colors.GetColor3d('Red'))
actor.SetMapper(mapper)

scalarBar = vtkScalarBarActor()
scalarBar.SetLookupTable(mapper.GetLookupTable())
scalarBar.SetTitle("Title")
scalarBar.SetNumberOfLabels(4)

hueLut = vtkLookupTable()
hueLut.SetTableRange(0,1)
hueLut.SetHueRange(0,1)
hueLut.SetSaturationRange(1,1)
hueLut.SetValueRange(1,1)
hueLut.Build()

mapper.SetLookupTable(hueLut)
mapper.SetScalarVisibility(0)

scalarBar.SetLookupTable(hueLut)

renderer = vtkRenderer()

renderWindow = vtkRenderWindow()
renderWindow.AddRenderer(renderer)
renderWindow.SetWindowName("ScalarBarActor")

renderWindowInteractor = vtkRenderWindowInteractor()
renderWindowInteractor.SetRenderWindow(renderWindow)

renderer.AddActor(actor)
renderer.AddActor(scalarBar)
renderer.AddActor2D(scalarBar)

exporter = vtkOBJExporter()
exporter.SetRenderWindow(renderWindow)
exporter.SetFilePrefix('out')
exporter.Write()

```