Base class is changed to USingleTargetWithSelectionTool.
When selection is provided, a UPreviewMesh for the unselected area is created and used.
A FSharedConstDynamicMesh3 is used to wrap either the original mesh or the selected submesh, and passed to the Operator (which also now takes a FSharedConstDynamicMesh3)
On shutdown, modified submesh is re-integrated into original mesh (in this case a trivial group copy suffices) and a new selection is emitted
#rb david.hill
#preflight 644036d1090323f9a31509d4
#jira UE-181651
[CL 25149588 by ryan schmidt in ue5-main branch]
ModelingTools: add support for writing to selected group layer, as well as new group layer, in ConvertToPolygonsTool (GrpGen in UI). Also add support for setting groups from existing layer, which (combined) allows copying groups between layers, duplicating existing layer, and so on.
#rb none
#preflight 630e3856e11248377555f234
[CL 21704364 by Ryan Schmidt in ue5-main branch]
- add FPolygroupLayer struct which is basically an identifier for a Polygroup layer, ie either the default mesh layer or one of the extended attribute layers
- add FPolygroupsGenerator::FindPolygroupsFromHardNormalSeams()
- add option to FPolygroupsGenerator::FindPolygroupsFromFurthestPointSampling() to constrain generation relative to an input polygroup set, ie only subdivide existing polygroups
- FMeshRegionGraph::BuildFromComponents now takes optional are-triangles-connected predicate, to allow links in graph to be disabled
- FPatchBasedMeshUVGenerator can now optionally generate new UV islands relative to an input Polygoup set, via new GroupConstraint input
#rb david.hill
#rnx
#jira none
#preflight 6142106e568b3a0001dbc2d0
#ROBOMERGE-AUTHOR: ryan.schmidt
#ROBOMERGE-SOURCE: CL 17522255 in //UE5/Main/...
#ROBOMERGE-BOT: STARSHIP (Main -> Release-Engine-Test) (v870-17433530)
[CL 17522278 by ryan schmidt in ue5-release-engine-test branch]
