[vtkusers] Re: How to update renderer from a point in the visualisation pipeline

[Goodwin Lawlor]

Ali - wrote:
> vtkImageImport can accept a C array as image data and, when connected to 
> the right visualisation pipeline, it can show the image. When the C 
> array is changes, the modified() method in vtkImageimport is invoked, 
> however, this does not update the render window and the change in the 
> image cannot be seen unless the render() method of the renderer is 
> manually called, eg by clicking on the render window.
> 
> How is it possible to update the render window whenever the pipeline is 
> modified? (What is the point of calling modified() when the final result 
> is not automatically rendered, anyway)

Hi Ali,

You could try by adding an observer to the vtkImageImport object, which 
fires a callback when a ModifiedEvent is invoked to re-render the window.

In tcl:

importer AddObserver ModifiedEvent {renWin Render}

With the new pipeline, it technically possible to create a pipeline 
which pushes data along to the render window rather than being pulled. I 
don't know if anyone has tried it yet though.

hth

Goodwin