[vtkusers] Memory usage and ReleaseDataFlag

Will Schroeder will.schroeder at kitware.com
Thu May 31 07:18:55 EDT 2001

Hi John-

Interesting questions.

At 12:43 AM 5/31/2001 +0100, you wrote:
>If a filter outputs a dataset and
>filter->SetReleaseDataFlag is true
>and the output is used as an input to multiple filters. Should the data 
>only be released when all filters consuming the output have updated. I 
>seem to be getting multiple updates and trouble.

In the old days, the number of consumers using the output of a filter was 
unknown. Therefore, the data was always released once any filter using the 
data object was done with it. It was up to the user to manually set the 
release data flag to cache branching situations and prevent reexecution. 
Ken recently added a list of consumers to the output data objects. Now It 
might be possible to set up some machinery to keep track of when all 
consumers finish with the data and then release at that point.

>part 2)
>An image filter outputting an image which is passed into vtkTexture can't 
>have ReleaseDataFlag(1) can it? Otherwise the texture reexecutes on every 
>render. True or false (true from where I'm sitting, but I don't really 
>believe it). Have I done something wrong.

I'm not sure about this.


William J. Schroeder, Ph.D
Kitware, Inc.
469 Clifton Corporate Parkway
Clifton Park, NY 12065
will.schroeder at kitware.com
1-518-371-3971 x102
1-518-371-3971 (fax)

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