Feature iso distance surface

• Adds improved handling of distance surface edges (#1950 (closed))
• freshened some of the iso-surface and sampling surface infrastructure to eliminate duplicate code, support cellZones for all iso-surface types.
• support multiple offsets for cutting planes and multiple iso-values

added enhancement feature labels

changed target branch from master to develop

assigned to @andy

cellZone restrictions can either be applied prior to the calculating the iso-surface or (for cell and topo variants) they can be applied via cell blocking within the algorithm. This avoids the overhead of creating an additional subMesh and associated subFields. Currently the simpleSubMesh is off by default, but may choose to change that in the future.

added support for isoValues

• culls any duplicate values
• currently all the resulting faces are joined together into a single common surface. Although the sampling origins are denoted with surface zones, since there is no reasonable way to handle these further on, the information isn't yet useful.

added support for plane offsets

• works like the runTimePostProcessing VTK variant. Can be useful when creating multiple slices for channel flow, for example. (@timofeymukha perhaps?)
• similar notes about combined surfaces as per isoValues comments.

Handling of ragged edges possible with different methods. The largestRegion method works robustly for solving the leaking of edges through thin walls.

The absolute distances from the original surface (showing ragged bits).

After using the mesh topology to clean things up, retaining the largest contiguous cuts.

• @Prashant for testing (only minor changes from the earlier preview version).
• @Mattijs for comments etc.

added 6 commits

• 155b1ba4...c51bfdcd - 3 commits from branch develop
• c18ce835 - ENH: improvements for managing iso-surfaces
• cb9c5ec4 - ENH: unify sampling code for isoSurfaces, support multiple offsets
• 19df50b4 - ENH: additional filtering for distance surface (#1950 (closed))

Compare with previous version

approved this merge request

added 31 commits

• 19df50b4...4c7f92d2 - 28 commits from branch develop
• 8fe0d1ba - ENH: improvements for managing iso-surfaces
• 7a99866d - ENH: unify sampling code for isoSurfaces, support multiple offsets
• 4c3a95c8 - ENH: additional filtering for distance surface (#1950 (closed))

Compare with previous version

mentioned in commit 7754e5bd

merged