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

[Amy Squillacote]

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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