Change the radius of picked actor (vtkSphereSource)

I’m following this example
which shows how to change color of the picked actor which is a vtkSphereSource. However, how is it possible to change the radius of the picked actor? there isn’t any SetRadius in the properties of the actors. How can I reach to the source from the actor? I’m thinking something like actor.GetMapper().GetSource().SetRadius() but there is no GetSource, I tried GetInputData too which doesn’t led me to the place I can SetRadius


I have found this example here which is written in C++, I’m interested in VTK Javascript or Python, There is not a getProducer for actor.getMapper().getInputData() as I saw.

// Now we retrieve the source object from vtkActor reversely, 
// meaning we don't use the spheresource object we instantiated
// above directly, 
// instead we retrieve a reference to the spheresource through the
// actor.
// An advantage of this concept might be that we don't need to
// maintain the source object anymore 
// in a more complex application.
// To demonstrate that we can modify properties of the spheresource
// through this reference
// beside changing some properties of the actor (in this example we
// change actor's x-position), 
// we change the radius of the spheresource as well.
// next two lines are the core lines for reverse access
vtkSmartPointer<vtkAlgorithm> algorithm =
  sphereActor->GetMapper()->GetInputConnection(0, 0)->GetProducer();
vtkSmartPointer<vtkSphereSource> srcReference =

float origRadius = srcReference->GetRadius();
for (int i = 0; i < 360; ++i)
  // change radius of the spheresource
  srcReference->SetRadius(origRadius * (1 + sin((float)i/180.0 * vtkMath::Pi())));
  // change x-position of the actor
  sphereActor->SetPosition(sin((float)i/45.0 * vtkMath::Pi())*0.5, 0, 0);
// Thanks to the usage of vtkSmartPointer there is no explicit need
// to free any objects at this point.


Hi, Travis,

You can try changing the actor’s scale with, for example, myActor.setScale(2.0, 2.0, 2.0). This will double the sphere’s radius as rendered.