                                                                level_snap
Chapter 8 Display and Level Operations

level_snap

*   This command will snap all vertices of the objects in a given set (0 - 31)
*   to the nearest vertex or side of an object on the specified level (32 - 95)
*   if it is within a given search radius distance.
*    
*        level_snap s l1 l2 r u p
*
*   Snaps all vertices of objects in set s (0 - 31) to the vertices/sides of
*   objects on level ln (32 - 95), if they are within radius r.  The units of
*   radius r are defined by c, the units code, according to the preference 
*   code p.
*   ___________________________________________________________________________
*   Options/arguments:
*
*        s         Set number (0 - 31); (0 = all objects)
*        l1        Lower bound level number (of levels to be snapped to) 
*                  valid entries are 32 to 95, inclusive.
*        l2        Upper bound level number (of levels to be snapped to) 
*                  valid entries are 32 to 95, inclusive.
*        r         Snap radius; must be a positive number and may be decimal.
*                  The units of r are defined by the units code, c.
*        u         Length units code, where:
*                     0 = pixels
*                     1 = map inches
*                     2 = ground feet
*                     3 = ground miles
*                     4 = map centimeters
*                     5 = ground meters
*                     6 = ground kilometers
*        p         Snapping Preference code, where:
*                     1 = snap each vertex to nearest line or vertex
*                         in level range specified.
*                     2 = snap each vertex preferentially to a vertex
*                         in level range specified, even if a line is closer.
*                     3 = snap each vertex to nearest line or vertex 
*                         in level range specified.  Then, add vertices 
*                         between snapped positions so that all vertices 
*                         will be exactly matched.  This option is normally 
*                         the one used to SNAP TO A TEMPLATE or FRAME.
*                     4 = snap each vertex only to a node or segment endpoint.
*                         This option is normally the one used to SNAP TO
*                         ADJACENT MAPS (EDGMATCHING).
*   ___________________________________________________________________________
*   Example(s):
*
*   To snap the map border polygon (which has already been placed in set 15)
*   vertices, within 3 pixels of the geodetic window, to the window, enter:
*
*        level_snap 15 32 32 3 0 3
*    
*   (the geodetic window is automatically generated when the map's geodetics
*   are registered; it follows longitude and latitude lines which are usually
*   curved on the map, in the most frequently used projections)
*
*   To snap all map edge nodes (which have already be put in set 6) to the 
*   nodes on levels 88-91 (edgemaps) for edgematching, within a tolerance
*   of 2.5 pixels enter:
*    
*        level_snap 6 88 91 2.5 0 4
*   ___________________________________________________________________________
*   See also:
*
*             import, level_clear, level_dup, level_icopy, level_snap, all set_
*             and crit_ commands
*   ___________________________________________________________________________
