Dynamic data visualization in VTK?

[Randall Hopper]

Maneesh Yadav:
 |In my application I have a sets of data (just positions really), ...But
 |this data can change (the positions evolve with time).  ... Does VTK
 |have; or is there any generally accepted methodology that dictates how
 |the visualzation of dynamic data should be handled?
...

Will Schroeder:
 |as time changes, regenerate the point coordinates (you'll probably want
 |to send a Modified() to make sure that the glypher knows to reexecute),
 |and then rerender. Something like:
 |

<<<Paraphrased:  Points -> PolyData -> Glyph3D -> PolyDataMapper -> Actor  >>>

 |for each time step {
 |         regenerate point coordinates
 |         glypher Modified()
 |         renWin Render
 |}

Will, I had this same question not long ago in a similar point-glyphing
pipeline.  I reverted to another pipeline structure, but I'm still curious
if/how this pipeline structure could have worked, and why we have to tell
the Glyph object it's modified (versus the PolyData for example).

Please stop me where I'm wrong.  But intuitively it seems to me that when
we set new points on a PolyData object, that should mark it as "modified".
When the pipeline is reevaluated, VTK should automatically detect that the
PolyData input of Glyph3D is modified, and thus Glyph3D should be
reexecuted.  Similarly, PolyDataMapper should reexecute since its input
changed, and ditto for Actor.

What is it that I'm missing here?  I'm puzzled why we have to tell any VTK
objects they are modified.  Shouldn't the PolyData.SetPoints() have done
that?

Thanks,

Randall

-- 
Randall Hopper
aa8vb at yahoo.com
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