[Paraview] [EXT] Re: Questions on Add Selection/Subtract Selection

[Dennis Conklin]

Utkarsh,

How about a "Freeze Selection" choice like in Find Data that would convert a frustrum selection into an ID-based selection which would enable the use of Add Selection using another frustrum or any of the other Selection tools.

Thoughtfully yours,
Dennis

-----Original Message-----
From: Utkarsh Ayachit [mailto:utkarsh.ayachit at kitware.com] 
Sent: Tuesday, February 13, 2018 10:57 AM
To: Dennis Conklin <dennis_conklin at goodyear.com>
Cc: Paraview (paraview at paraview.org) <paraview at paraview.org>
Subject: [EXT] Re: [Paraview] Questions on Add Selection/Subtract Selection

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Dennis,

> Why are “Select Cells/Points Through” not using Add Selection – in 
> many cases it is necessary to select using different interactive 
> methods to get the final desired selection.

An implementation nuance, and no one asked for it :). The extract filter just support extracting a single frustum. We, in theory can make it support multiple additive frustums, but some additive, some subtractive will make it a trickier implementation. Of course, doable, not since no one asked for it, it never got around to getting implemented.

> Should Select Block be divided into “Select Block Cells” and “Select 
> Block Points”

Good idea.

> so that this selection method could be combined with Select 
> Cells/Points On/Through with the “Add Selection” to finetune a selection.
> Alternately should “Select Block” be smarter and only select Block 
> Cells if the current Selection is Cells, or only select Block Points 
> if the current Selection is Points (and add them to the existing 
> selection instead of replacing it?

Ah! That's cool and not easily supportable the way things are currently. But Berk and I were chatting and we have an approach to support combining multiple selections add/remove/etc. nicely. Now just convince Alan to make it a priority and I'd love to have it sorted out for the SC release ;).

Utkarsh