[Paraview] Auto-Execute Plugin on Selection

[Eric E. Monson]

Hey Christian,

Hopefully someone more clever and experienced than I am can think of a way for you to do what you want, but I'm not sure that it's possible with how ParaView deals with selections right now.

As the ParaView developers consider how to improve the usability of the program in future revisions, I think it might not hurt to look at the way PV deals with selections and selection tools. VTK and PV development in recent years has added more capabilities for interactive probing and exploration of data, in addition to the more traditional scientific visualization tasks. Of course, performance on huge data sets will always have to be a top priority in PV development, but I think users who are used to any other interactive software for exploring data are surprised by the awkwardness of the selection procedure: 1. There is no persistence of the selection tools. 2. If the Selection Type is anything other than IDs for selecting "on" or Frustum for "through", you have to keep re-choosing another option (like Global IDs) from the Selection Inspector after each selection. 3. If a filter takes a selection, there is no way to automatically use the active selection, there is only the Copy Active Selection button. 4. There is no idea of selecting "objects", whether that be pipeline objects or geometric objects like spheres or cubes. 

For my users, then, this means each time they want to make a selection to explore a different part of the data, they have to re-activate the proper selection tool, make a selection, change the Type to Global IDs, click in the pipeline to activate the selection-using filter, then copy the active selection. It's a bit ponderous, and they don't have the perspective of why these interaction choices were made in the context of visualizing huge SciVis data sets, they just want to be able to explore their data more naturally.

Anyway, please forgive me if you feel I've misused your thread for my more general statements, but I keep meaning to put Selections forward as a new topic for ParaView usability concerns.

Take care,
-Eric

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Eric E Monson
Duke Visualization Technology Group


On Apr 5, 2010, at 6:07 AM, Christian Werner wrote:

> Hi!
> 
> I'd like to know if there is a way to execute a macro on a certain event, e.g. when the user does a selection in the 3D viewer. The problem is that I have to select several object out of many candidates. Of course, I could just do a multiselection with using the Ctrl key, but for reasons of usability it has to be prevented that a selection can get lost. Take a look at the attached image and imagine you were analyzing this dataset for quite a while and already selected several objects with a multi select. On the next object you forget to press the control key while selecting... Bad luck... Everything is gone. You may start all over.
> So I thought maybe I could call a plugin whenever a selection is done. This plugin could just look up the x,y,z coordinates of the selection, which would already do the job for me. If this is not possible, would it be worthwhile looking into the source to ruthlessly "hack" this into Paraview?
> Or does somebody have any other good idea?
> 
> Maybe it would be nice to turn multiselection permanently on/off!
> 
> Best regards,
> Christian
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