[vtkusers] Help : how memory is used with VTK ?

[vidyadhar]

Hi Amy,
I am interested in the queries raised by Nicolas. He is willing to
compromise speed for memory. Actor's pipeline is updated when it is rendered
once. Is there some way to release these memory resources when the actor is
hidden without removing its pipeline? I think this can be useful even
without the speed/memory compromise.
Vidyadhar

----- Original Message -----
From: "Amy Squillacote" <amy.squillacote at kitware.com>
To: "Nicolas Cathaud" <nicolas.cathaud at gmail.com>; "VTK" <vtkusers at vtk.org>
Sent: Thursday, April 27, 2006 9:15 PM
Subject: Re: [vtkusers] Help : how memory is used with VTK ?


> Hi Nicolas,
>
> Assuming that you're saying you see a memory increase just before VTK
> first renders your model, then the reason is VTK's demand-driven
> pipeline.  VTK does not read data, run filters, etc. until something
> tells it to (rendering, in your case).
>
> This should also explain why the memory isn't freed when you hide
> part of your scene; memory was allocated when these parts of your
> scene were first rendered, and if the memory was freed just because
> you weren't rendering that part of the scene, then data would have to
> be re-read, filters re-executed, etc. when you wanted to render that
> part of the scene again.
>
> - Amy
>
> At 11:31 AM 4/27/2006, Nicolas Cathaud wrote:
> >Hello everybody,
> >
> >I have many questions about vtk and memory. When I load a big model with
VTK
> >(nearly 300.000 triangles), I notice that the memory clearly increases
just
> >before display. I just want to know if it's possible to avoid this, even
if
> >I lose in movement's fluidity. I can't find what consume this memory, and
> >I'm curious to know the reason of that. Is it an openGL mode which
allocate
> >a lot of memory in order to increase the performance ? Is it the data
> >structure of vtk ?
> >
> >My second question is how to free this memory when I want to hide an
element
> >of the scene. Indeed, I have many actors in my scene, and I want to have
the
> >possibility to hide or show this actors, so I use the commands "AddActor"
> >and "RemoveActor", but it didn't free the memory when there are no actor
in
> >the scene.
> >
> >Thank you for reading this message.
> >
> >Regards.
> >
> >Nicolas CATHAUD
> >
> >
> >
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