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

[Utkarsh Ayachit]

That's a temporary workaround. It won't be a good approach for large
datasets as frustum selection has the potential of selecting a large
number of elements. Since for ID based selections, each ID has to be
explicitly listed in the proxy state (so that it gets saved in state
files, python scripts etc.), it not intended to contain a large number
of values.

On Tue, Feb 13, 2018 at 2:21 PM, Dennis Conklin
<dennis_conklin at goodyear.com> wrote:
> 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
>
>  WARNING - External email; exercise caution.
>
>
>
> 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