# Emissive actor light up other actor with PBR?
**URL:** https://discourse.vtk.org/t/emissive-actor-light-up-other-actor-with-pbr/5415
**Category:** Support
**Created:** [March 20, 2021, 3:45pm UTC](https://discourse.vtk.org/t/emissive-actor-light-up-other-actor-with-pbr/5415 "2021-03-20T15:45:19Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@estan](https://discourse.vtk.org/u/estan)
#### Post date: [March 20, 2021, 3:45pm UTC](https://discourse.vtk.org/t/emissive-actor-light-up-other-actor-with-pbr/5415/1 "2021-03-20T15:45:19Z")
Hello,
Consider this example:
```python
import vtk
cubeSource = vtk.vtkCubeSource()
cubeMapper = vtk.vtkPolyDataMapper()
cubeMapper.SetInputConnection(cubeSource.GetOutputPort())
emissiveSource = vtk.vtkImageCanvasSource2D()
emissiveSource.SetScalarTypeToUnsignedChar()
emissiveSource.SetNumberOfScalarComponents(3)
emissiveSource.SetExtent(0, 1, 0, 1, 0, 0)
emissiveSource.SetDrawColor(255, 255, 255)
emissiveSource.FillBox(0, 1, 0, 1)
emissiveTexture = vtk.vtkTexture()
emissiveTexture.SetUseSRGBColorSpace(True)
emissiveTexture.SetInputConnection(emissiveSource.GetOutputPort())
cubeActor = vtk.vtkActor()
cubeActor.SetMapper(cubeMapper)
cubeActor.GetProperty().SetInterpolationToPBR()
cubeActor.GetProperty().SetEmissiveTexture(emissiveTexture)
cubeActor.GetProperty().SetEmissiveFactor(1.0, 0.0, 0.0)
cubeActor.SetPosition(-0.55, 0.0, 0.0)
sphereSource = vtk.vtkSphereSource()
sphereMapper = vtk.vtkPolyDataMapper()
sphereMapper.SetInputConnection(sphereSource.GetOutputPort())
sphereActor = vtk.vtkActor()
sphereActor.SetPosition(0.55, 0.0, 0.0)
sphereActor.GetProperty().SetInterpolationToPBR()
sphereActor.SetMapper(sphereMapper)
renderer = vtk.vtkRenderer()
renderer.AddActor(cubeActor)
renderer.AddActor(sphereActor)
window = vtk.vtkRenderWindow()
window.AddRenderer(renderer)
interactor = vtk.vtkRenderWindowInteractor()
interactor.SetRenderWindow(window)
interactor.Start()
```
Is there any way to have the emissive cube light up the sphere (give it a red tint), or must I turn to OSPRay for this?
---
### Author:  [@mwestphal](https://discourse.vtk.org/u/mwestphal)
#### Post date: [March 22, 2021, 11:44am UTC](https://discourse.vtk.org/t/emissive-actor-light-up-other-actor-with-pbr/5415/2 "2021-03-22T11:44:01Z")
FYI @Lfx_Paul
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### Author:  [@amaclean](https://discourse.vtk.org/u/amaclean)
#### Post date: [March 22, 2021, 10:36pm UTC](https://discourse.vtk.org/t/emissive-actor-light-up-other-actor-with-pbr/5415/3 "2021-03-22T22:36:22Z")
I am pretty sure it is not possible because the emissivity is just a texture on the surface. So you may have to use OSPRay.
Interestingly emissivity does not change when you change the light source so it is inherent to the cube in this case. E.g. add this after creating the renderer. You get a cyan light on the sphere but the colour of the cube is unchanged.
```python
light = vtk.vtkLight()
light.SetColor(0,1,1)
renderer.AddLight(light)
```
---
### Author:  [@estan](https://discourse.vtk.org/u/estan)
#### Post date: [March 25, 2021, 7:30am UTC](https://discourse.vtk.org/t/emissive-actor-light-up-other-actor-with-pbr/5415/4 "2021-03-25T07:30:31Z")
Alright, thanks @amaclean.
Do you know if there are any plans to add support for area lights to VTK’s own renderer?
---
### Author:  [@amaclean](https://discourse.vtk.org/u/amaclean)
#### Post date: [March 27, 2021, 10:18am UTC](https://discourse.vtk.org/t/emissive-actor-light-up-other-actor-with-pbr/5415/5 "2021-03-27T10:18:39Z")
I am not the best person to answer this , however, to my knowledge, I don’t know of any plans.