# 2.6. Version 5.18 (2024/02/23)

New Features

  - A skinned set of shell elements can now be generated from a source surface can be created as a skinned shell. This can be useful in MPMD coupling applications with surfaces deforming at differing rates.

  - Added new enclosure error and warning tolerance settings to check for enclosure rowsum errors. Prior releases would not error on bad rowsum errors by default, but in 5.18 there is now a default error tolerance above which row sum errors will trigger a fatal error. Check the enclosure radiation commands for the appropriate syntax.

  - Ray Tracer:

      - Added optional modular block definition for ray tracer flux model

      - Expanded ray tracer capability to enable modeling of banded radiation

  - Adaptivity:

      - Small change to enable adaptivity to be compatible with element fields (for chemeq)

      - Added timers to sierra log output for various adaptivity operations

      - Automatically un-refine elements on blocks that do not have a marker rule, to allow mesh to fully un-refine

Upcoming Deprecations (will warn in 5.18)

  - Using the `skinned_blocks` location in Calore-style BCs to automatically skin blocks is deprecated. The desired skinned surface can be explicitly created as a skinned surface.