Enhancements / Additions:

• Added ability to generate periodic surface grids.
• The gui reflects the draw-state of the selected cutting plane.
• Customizable GUI set-up file to store user start-up preferences.
• Added geometric functionality for Discrete geometry and CAPRI data:
  • Compute closest point
  • Compute surface intersections and projections (the result is a physical curve)
  • Compute tangent and surface normal vectors
  • Compute Carpet surfaces
• Added ability to assign and export boundary conditions for the USM3D flow solver.
• Added support to read and write and VGRID files.
• The UG_IO library now allows for a volume id flag specified per element.  This is supported in the following formats: CGNS, FGRID/UFAST, NASTRAN, and UGRID.  A toggle has been added to the File I/O Read File Window to specify whether to retain the volume id flags or not.  By default, the volume id flags are not retained.  The command line option to retain the volume id flags is -retainvolids.
• Modified the Grid Tools to retain the volume id information.  Added three command line options to voltool to assign and extract sub-volumes based on id.
  • -extractelem: Extract the specified volumes(s) and write them to the specified output grid file.
  • -assignelem: Assigns a volume id to all elements between the surfaces specified using -surfid1 and -surfid2.
  • -auto: If used with -assignelem, automatically assigns a volume id to all elements based on the number of sub-volumes formed by closed interior surfaces.
    If used with -extract or extractelem, automatically extracts each volume id found in the grid and writes each sub-volume to a separate grid file.
• Added command line option -compress_tag to surftool to renumber all surface ids so that they are numbered consecutively.

Bugs Fixed:

• Graphics bug fixed that caused surface meshes to be drawn incorrectly.  Intermittent bug that only showed up when surface mesh changed.
• Corrected behavior of the Orthogonal Surface Sweep.  The direction of the sweep is determined automatically, rather than assuming the relative direction of the curve path (directorix).  The swept surface is always along the directorix, unless the Reverse toggle is selected.
• Corrected behavior of the Average Surface generation.  The surfaces normals are aligned.
• Corrected bug that ignored user requests to not overwrite files when the file already exists.
• Corrected Save State related problems:
  • Corrected minor memory leaks
  • Corrected problem storing interior point spacings
  • Corrected problem with Vectors being drawn incorrectly
  • Synchronized the settings of the Visible Graphics List with the Save State file
• Corrected memory leak related to deleting Groups.
• Corrected problem with generating composite surface grids.  Occurred if the composite surface grid was generated first (introduced in version 5.51).

Known Problems and Limitations:

• Trimming IGES-tagged periodic surfaces.