ODRAG                                                      Menu: (MWALS) MWUTL
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Places openings in multi-layer walls.

         1.  (IND) wall to insert opening
         2.  (Y/N) confirm choice
         3.  (Y/N) option: y - rectangle-shaped, n - pre-designed opening <y>
      if `n' is replied:
         4.  (CHAR) pre-designed opening name (8 chars.)
      for all options:
         5.  (NUM) opening width (greater than 0)
         6.  (NUM) height of opening (0 or greater)
         7.  (NUM) height above floor (0 or greater)
         8.  (POINT) opening position (Alt+1 - change opening orientation)
      if opening is from the General Opening Library (L$OPEN) and one or
      more combinations exist for the wall/opening and specified direction:
         9.* (Y/N) solution acceptable?
      if `n' is selected repeatedly:
         10. (Y/N) all options were introduced, wish to loop again?
      for all options:
         11.*(Y/N) y-another position, n-another wall, <ENTER>-displacement
      if ENTER is pressed:
         12. (POINT) start of displacement (fixed point in model)
         13. (POINT) end of displacement (point on opening)
         14. (NUM) displacement

Description
This command places openings in multi-layer walls.  If an opening has
previously been selected during the current work session, that opening is the
default and will be placed by this command.  If no opening has been selected,
or an opening other than the default is to be placed, it is necessary to
access this command via the graphic library of openings, i.e., the pull-down
menu, or specify the library and opening name using the \setob command.

From the CREATE sub-menu in the pull-down menu select:
         * MULTI-LAYER WALLS
         * PICK LIBRARY OPEN.

A list of libraries appears on screen.  Select the library that you require.
A graphic menu, together with the opening name and width, appears on screen.

NOTE: Only openings in the General Opening Library may have independent end
conditions attached to them (using the \clib command).  Openings in other
libraries may include the termination of the wall in which they will be
inserted as an integral part of the opening but they will not behave as end
conditions (replace, etc.).

Openings that form part of a combination do not appear with end conditions
attached in the graphic library, but if end conditions have been combined with
the opening (using the \clib command) they will appear when the opening is
placed in the wall.

Using the Cursor to Select the Required Opening

Indicate the wall in which you wish to insert the opening and confirm that the
system has identified the intended wall.  You are asked whether the three
dimensional opening is to be a simple rectangular void or a specially
pre-designed one.  If you select a rectangular void it will adopt the
thickness of the wall.

If you select a special pre-designed opening, specify its name.  It can be any
negative solid.  It can be created as a 1 x 1 x 1 unit that the system will
stretch to the specified width and height, and wall thickness.  Alternatively,
it may be created with real dimensions (except for thickness which should be 1
unit).  In this case, the width and height must be specified as `1' in order
to maintain the original dimensions.

If the opening was defined as a stretchable opening when included in the
opening library (using the \olib command) you are asked to state the opening
width.  State the opening height and starting height above the floor.

The opening appears attached to the cursor in the indicated wall so that it is
free to "slide" along the length of the wall.

Changing the Symmetry of the Opening

At this stage you may switch the symmetry of the opening.  Use <Alt>+1 to
switch between the four possible symmetries (left, right, inward opening,
outward opening).

The cursor is attached to the opening at one of its sides.  If you wish to
switch the cursor to the other side, press <Alt>+2.

Point to the desired position.  The wall will be broken and the opening will
be placed in the position you indicated.

If the opening has been selected from the General Openings Library, it will
appear together with the combined end conditions that were specified using the
\clib command.  You will be asked if the solution is acceptable.

If you reply negatively, the next combination will be displayed.  If you
continue to reply negatively the system will inform you when all the
combinations in the library have been exhausted and ask you whether you wish
to repeat the cycle.  If no combination (for the wall/opening and direction)
has been defined, the opening will be placed as it exists in the General
Opening Library (L$OPEN) and the system end conditions (straight lines) will
be attached.  If you do not wish to repeat the cycle you will end the command.

Where the opening/end condition combination that is being placed has been
defined (using the \clib command) for a symmetrical wall (i.e., symmetrical
layer colors as well as layer thickness) you will be able to switch the
symmetry of the opening between four possible symmetries, i.e., left, right,
inward opening, outward opening).  All combinations are available regardless
of opening direction.

For asymmetrical walls, combinations must be created for both inward and
outward opening directions (using the \clib command).  When you place the
opening, you determine the symmetry using the <Alt>+1 keys.  Depending on the
direction of the placed opening (inward or outward), the system will present
you with combinations in that direction only.

The system will prevent you from placing an opening in a position that
projects beyond the end of the wall.

You are now presented with three options.  You may place another of the same
opening in the same wall, in another wall, or you may specify an accurate
displacement for the opening you have just placed.

If you select this option you will be asked to indicate two points; one on the
model and one on the opening.  The system will return the exact distance
between these two points in the command line.  If the distance or displacement
is not satisfactory you may change it.  When you enter the new value, the
opening will move to the new position so that the displacement between the two
points will be exactly that which you specified.

You are presented with the three previous options repeatedly until you select
a new command.

NOTE: The maximum number of openings allowed in a single wall is 30.
