[Paraview] Questions on Add Selection/Subtract Selection

[Utkarsh Ayachit]

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