Empty rendering after scaling

Hi,

I first scaled my volume to [0, 1]^3 by:

reader = OpenDataFile("./example_volume.vti")
reader.UpdatePipeline()
transform = Transform(Input=reader)
transform.Transform.Scale = [1/512, 1/512, 1/512]
transform.UpdatePipeline()

But when I renderer it, I have an empty image. Here is my code for rendering:

Show()
Render()
camera = GetActiveCamera()
bounds = transform.GetDataInformation().GetBounds()
center = [(bounds[0] + bounds[1])/2, (bounds[2] + bounds[3])/2, (bounds[4] + bounds[5])/2]
camera.SetFocalPoint(*center)
camera.SetPosition(6, 6, 6)
camera.SetViewUp(0, 1, 0)

Could you help me with it? Thank you