STRCS                                                      Menu: (POLYG) PRISM
==============================================================================
Creates a three-dimensional staircase.

         1. (NUM) stairs type: 1-linear, 2-winding, 3-spiral,
                                                         <ENTER>-graphic lib.

      FOR OPTIONS 1-LINEAR AND 2-WINDING
      if option 1 (linear) is selected in prompt 1:
         2. (NUM) flight: 1-single, 2-parallel, 3-three, 4-four, 5-two(90)
      if option 2 (winding) is selected in prompt 1:
         2. (NUM) flight type: single-6,7,8,9, double-10,11,12, triple-13
      if  option 1 or 2 is selected in prompt 1:
         3. (POINT) staircase starting point
         4. (POINT) staircase direction
         5. (NUM) width of flight (greater than 0) <1.1>
      if option 1 (single) is selected in prompt 2:
         6. (NUM) 1st param.: 1-Rise, 2-Tread, 3-Height, 4-Length,
                                                         5-End pt., 6-No.
      if option 2 to 13 is selected in prompt 2:
         6. (NUM) 1st param.: 1-Rise, 2-Tread, 3-Height, 5-End pt., 6-No.
      if option 1 is selected in prompt 6:
         7. (NUM) rise of stair (R)
      if option 1 (single) is selected in prompt 2:
         8. (NUM) second parameter: 3-Height, 4-Length, 5-End pt., 6-No.
      if option 2 to 13 is selected in prompt 2:
         8. (NUM) second parameter: 3-Height, 5-End pt., 6-No.
      if option 2 is selected in prompt 6
         7. (NUM) tread of stair (T)
      if option 1 (single) is selected in prompt 2:
         8. (NUM) second parameter: 3-Height, 4-Length, 5-End pt., 6-No.
      if option 2 to 13 is selected in prompt 2:
         8. (NUM) second parameter: 3-Height, 5-End pt., 6-No.
      if option 3 is selected in prompt 6:
         7. (NUM) total height (floor to floor) (H)
      if option 1 (single) is selected in prompt 2:
         8. (NUM) second parameter: 1-Rise, 2-Tread, 4-Length, 5-End pt., 6-No.
      if option 2 to 13 is selected in prompt 2:
         8. (NUM) second parameter: 1-Rise, 2-Tread, 5-End pt., 6-No.
      if option 4 is selected in prompt 6:
         7. (NUM) total length (first stair to floor) (L)
         8. (NUM) second parameter: 1-Rise, 2-Tread, 3-Height, 5-End pt., 6-No.
      if option 5 is selected in prompt 6:
         7. (POINT) flight end point
         8. (NUM) second parameter: 1-Rise, 2-Tread, 6-No.
      if option 6 is selected in prompt 6:
         7. (NUM) total number of stairs (N)
      if option 1 is selected in prompt 2:
         8. (NUM) second parameter: 1-Rise, 2-Tread, 3-Height, 4-Length,
                                                                    5-End pt.
      if option 2 to 13 is selected in prompt 2:
         8. (NUM) second parameter: 1-Rise, 2-Tread, 3-Height, 5-End pt.
      if option 1 is selected in prompt 2, and if the second parameter has
      not been changed by the system:
         9. (Y/N) R- n T- n H- n L- n N- n 2h+b= n , confirm ?
      if option 2 to 13 is selected in prompt 2, and if the second parameter
      has not been changed by the system:
         9. (Y/N) R- n T- n H- n N- n 2h+b= n , confirm ?
      if option 1 is selected in prompt 2, and if the second parameter has
      been changed by the system:
         9. (Y/N) ~ R- n T- n H- n N- n 2h+b= n , confirm ?
      if option 2 to 13 is selected in prompt 2, and if the second parameter
      has been changed by the system:
         9. (Y/N) ~ R- n T- n H- n L- n N- n 2h+b= n , confirm ?
      if options 1 or 2 were selected in prompt 1:
         10.(NUM) number of floors <1>
      if options 2, 5, 10, 11, or 12 were selected in prompt 2:
         11.(NUM) No. of steps in first flight (total: n )
      if options 3 or 13 were selected in prompt 2:
         11.(NUM) No. of steps in 1st & 2nd flights (N N) (total: n )
      if option 4 was selected in prompt 2:
         11.(NUM) No. of steps in 1st, 2nd & 3rd flights (N N N) (total: n )
      if option 2 was selected in prompt 2:
         12.(NUM) distance between flights <0.3>
      for all options:
         13.(Y/N) option: y-light steps n-massive steps
      if 'y' was selected in prompt 13:
         14.(NUM) thickness of step, <ENTER> max. thickness
      if options 1 to 5 in prompt 2, if 'y' was selected in prompt 13:
         15.(NUM) thickness of landing, <ENTER> -max. thickness
      if option 1 was selected in prompt 2:
         16.(NUM) handrail: 1-left, 2-right, 3-both, 4-none <3>
      if options 2 to 13 were selected in prompt 2:
         16.(NUM) handrail: 1-internal, 2-external, 3-both, 4-none <3>
      for all options:
         17.(NUM) balusters: 1-middle of step, 2-step end, 3-none <1>
      for all options in prompt 2 except option 1:
         18.(Y/N) turn in landing: y-right ,n-left
         19.(Y/N) draw option: y-3D, n-2D

      FOR OPTION 3-SPIRAL (in prompt 1)
         2. (POINT) flight center point
         3. (POINT) direction point of first step
         4. (NUM) flight inner radius (greater than 0)
         5. (NUM) flight width (minimum: 0.6 m.)
         6. (NUM) 1st prm.: 1-Rise, 2-Tread, 3-Ht., 4-Tot.A, 5-End pt.,
                                                                 6-No.,7-St.A
      if option 1 was selected in prompt 6:
         7. (NUM) rise of stair (R)
         8. (NUM) second parameter: 3-Height, 4-Total Angle, 5-End pt., 6-No.
      if option 2 was selected in prompt 6:
         7. (NUM) tread of stair (T)
         8. (NUM) second parameter: 3-Height, 4-Total Angle, 5-End pt., 6-No.
      if option 3 was selected in prompt 6:
         7. (NUM) flight total height (H)
         8. (NUM) second parameter: 1-Rise, 2-Tread, 6-No., 7-Stair Angle
      if option 4 was selected in prompt 6:
         7. (NUM) flight total angle (greater than 0)
         8. (NUM) second parameter: 1-Rise, 2-Tread, 6-No., 7-Stair Angle
      if option 5 was selected in prompt 6:
         7. (POINT) flight end pt.
         8. (NUM) second parameter: 1-Rise, 2-Tread, 6-No., 7-Stair Angle
      if option 6 was selected in prompt 6:
         7. (NUM) total number of stairs (N) (greater than 3)
         8. (NUM) second parameter: 1-Rise, 2-Tread, 3-Ht., 4-Tot.A,
                                                            5-End pt., 7-St.A
      if option 7 was selected in prompt 6:
         7. (NUM) single stair angle
         8. (NUM) second parameter: 3-Height, 4-Total Angle, 5-End pt., 6-No.
      if the second parameter has not been changed by the system:
         9. (Y/N) R- n T-  H- n A- n Tot.A- n N- n , confirm?
      if the second parameter has been changed by the system:
         9  (Y/N) ~ R- n T-  H- n A- n Tot.A- n N- n , confirm?
         10.(NUM) thickness of step, <ENTER>-max. thickness
         11.(NUM) handrail: 1-internal, 2-external, 3-both, 4-none <3>
         12.(NUM) balusters: 1-middle of step, 2-step end, 3-none <1>
         13.(Y/N) wish to add center column ?
         14.(Y/N) climbing direction: y-clockwise, n-counter clockwise
         15.(Y/N) draw option: y-3D, n-2D

Description

This command draws a 3-dimensional staircase.

State whether the stair type is to be a linear (straight flights), winding or
spiral, or press <ENTER> to select any type from a graphic library.

If you select a linear flight, you may select one of the following types:
         1 - single flight (straight)
         2 - two parallel flights (180 degree staircase landing)
         3 - three flights (U-shaped staircase with landings)
         4 - four flights (rectangular staircase with landings)
         5 - two flights (90 degree staircase landing)

Type a number (1 to 5) to select a linear type flight.

If you select a winding type staircase, you may select one of the
following types:
         6 - single flight with 3, 5 or 7 winding steps at the top of the
             flight
         7 - single flight with 3, 5 or 7 winding steps at the bottom of the
             flight
         8 - single flight with 3, 5 or 7 winding steps at the top and
             bottom of the flight in the same direction
         9 - single flight with 3, 5 or 7 winding steps at the top and bottom
             of the flight in opposite directions
        10 - 90 degree staircase with 3, 5 or 7 winding steps
        11 - 180 degree staircase with 6, 10 or 14 winding steps
        12 - 180 degree staircase with 5, 9 or 13 winding steps
        13 - U-shaped staircase with 3, 5 or 7 winding steps

Type a number (6 to 13) to select a winding type flight.

LINEAR AND WINDING TYPE STAIRCASES

Specify the starting point of the staircase, i.e., the lower right point of
the first step when the stairs turn left and the lower left point of the first
step when the stairs turn right.

Specify a point to fix the direction of the stairs.  The projection of the
line between the two points on the XY plane will be the direction of the
stairs (upwards).

Specify the width of the flight.

Select which stair parameter you will specify as the first.  This will be a
fixed parameter and will not be changed by the system when calculating the
other parameters.

The options are:

Parameter       Description
1 - Rise        Height of individual step
2 - Tread       Width of individual step measured at 90 to the rise (in the
                case of winding stairs this is measured 60 cm from the narrow
                side of the step)
3 - Height      Total height of the staircase (floor to floor)
4 - Length      Total length of the staircase (for single flight linear
                stairs only)
5 - End pt.     End point of the flight
6 - No.         Number of stairs in the flight

Enter a value for this parameter.

Select which stair parameter you will specify as the second.  Enter a value
for this parameter.  This, together with the first parameter, completes the
information required by the system to calculate the remaining staircase
parameters.  The system executes the parameter calculation for the stairs and
checks the result against the ranges that are set using the \astrs command.

For example, if the first parameter was Rise, then the second parameter should
be Height, End point or No.  (Length, for single linear flight only).  Tread,
in addition to Rise, which has been specified, will not provide sufficient
information to execute the calculation of the stairs so it will not be
presented as a second parameter option.

The program will calculate the complete set of parameters and display the
results.  If the second parameter you entered has been modified, a `~' sign
will be added to the beginning of the results line.

Check all the parameters.  If they suit your design, confirm the solution.  If
not, enter `n' and change one of the parameters.

For example, if you entered height=3m as a first parameter and rise=0.17m as
the second, you may use 17 stairs and 0.176470m rise or 18 stairs of 0.16667m.
Both answers will give a 3m height and will be close to the rise you wanted.
If the first answer you get is 17 stairs and you want 18, do not confirm the
parameters, enter height=3 as the first parameter and number of stairs=18 as
the second.  This gives you full control over the design of the staircase.

NOTE: After confirming the parameters, do not use the repeat command function,
i.e., do not use <F12> or B3 of the mouse.

Enter the number of floors in the flight.

The rest of parameters vary according to the layout you have selected for the
staircase.

If you selected options 2 (two parallel flights), 5 (two flights at 90), 10
(90 degree staircase with 3, 5 or 7 winding steps), 11 (180 degree staircase
with 6, 10 or 14 winding steps) or 12 (180 degree staircase with 5, 9 or 13
winding steps) in prompt 2, enter the number of stairs in the first flight;
the remainder of the stairs will be created in the second flight.

If you selected options 3 (three flights) or 13, enter the number of stairs
for the first and second flights; the remainder of the stairs will be created
in the third flight.

If you selected option 4 (four flights), enter the number of stairs for the
first and second and third flights; the remainder of the stairs will be
created in the fourth flight.

If you selected option 2, specify the distance between flights.

For all options, specify if the steps are light or massive.  Light steps are
individual steps where the underside of the step is parallel and of identical
shape to the top surface of the step.  Massive steps are steps that are
monolithic and whose undersides assume the general slope of the stair.

If light steps are selected, specify the thickness of the step or press ENTER
for the maximum thickness.

You have the option to create a handrail.  If you selected option 1 (linear),
select the location of the handrail to be on either or both sides of the
staircase, or not to create a rail at all.  If you selected options 2-13,
select the location of the handrail to be on the internal, external or both
sides of the staircase, or not to create a rail at all.

You have the option to create a balusters.  Select the location of the
baluster to be in the middle of the step, on the end (nose) of the step or not
to have a baluster.

For all the flight types selected in prompt 2 except type 1 (linear), specify
whether the direction of the turn in the landing is to be right or left.

The staircase is now ready to be drawn.  Specify whether to draw the staircase
in 2D or 3D.

If you have specified a winding staircase, the lower and higher limit to the
number of stairs in a single flight (default 3 or as specified in the \astrs
command) will be ignored.

The resultant parameters will be calculated by the system within the
permissible ranges specified using the command \astrs.  If the calculated
values are accepted, the system will create the staircase.  If you selected a
3D drawing the solid entity may be copied, manipulated, sectioned or modified
like any other entity.  All the parameters of the staircase are calculated
based on the parameters specified.

Flights are always measured (in plan) from the first (lowest) rise to the last
(highest) tread, inclusive.  The top step (in elevation) will be the same
level as the upper floor slab.  The bottom plane of the staircase solid will
be the same level as the lower floor slab.

The landing created in stair types 1 to 5 is an independent solid slab with
the same width and length as the flight width and the same height as the
specified or calculated rise.

Each step in the winding part of a staircase (types 6 to 13) and each step in
a light staircase are also independent entities.

In linear staircases the thickness of the "waist" (measured perpendicularly
from the underside of the flight to the line of the flight) is an internal
parameter determined by the system and cannot be set by the user.  Adjustments
may be made if necessary using the \movef and \movep commands.

Spiral Staircase

Specify the center point of the flight, i.e., the point around which the
spiral staircase will be created.  Specify a point to fix the direction of the
stairs.  The first rise will be created on the imaginary line (or projection
of the line) that connects these two points.

Specify the inner radius of the flight.

Specify the flight width.

Select which stair parameter you will specify as the first.  This will be a
fixed parameter and will not be changed by the system when calculating the
other parameters.

The options are:

Parameter       Description
1 - Rise        Height of individual step
2 - Tread       Width of individual step measured at 90 to the rise (in the
                case of winding stairs this is measured 60 cm from the narrow
                side of the step)
3 - Ht          Total height of the staircase (floor to floor)
4 - Tot. A      Total angle of the flight . . .
5 - End pt.     End point of the flight
6 - No.         Number of stairs in the flight
7 - St.A        Angle of a single stair

Enter a value for this parameter.

Select which will be the second parameter and enter its value.

This, together with the first parameter, completes the information required by
the system to calculate the remaining staircase parameters.  The system
executes the parameter calculation for the stairs and checks the result
against the ranges set using \astrs.

For example, if the first parameter was Rise, then the second parameter should
be Height, Total Angle, End point or No.  Tread, in addition to Rise, which
will not provide sufficient information to execute the calculation of the
stairs so it will not be presented as a second parameter option.

The program will calculate the complete set of parameters and display the
results.  If the second parameter you entered has been modified, a `~' sign
will be added to the beginning of the results line.

Check all the parameters.  If they suit your design, confirm the solution.  If
not, enter `n' and change one of the parameters.

Now specify the thickness for each step or press <ENTER> for the maximum
thickness.

Specify the location for the handrail to be internal, external, both or not to
have a handrail.

Specify the location of the balusters to be the middle of the step, the end
(nose) of the step, or not to have balusters.

Specify whether you want to add a center column.  Then specify the climbing
direction of the spiral staircase to be clockwise or counterclockwise.

The spiral staircase is now ready to be drawn.  Specify whether to draw it in
2D or 3D.

The resultant parameters will be calculated by the system within the
permissible ranges specified using the command \astrs.  If the calculated
values are accepted, the system will create the staircase.  If you selected a
3D drawing the solid entity may be copied, manipulated, sectioned or modified
like any other entity.  All the parameters of the staircase are calculated
based on the parameters specified.

The following drawing shows examples of spiral staircases using various
combinations of available options:

NOTE: You may use the \qent command to retrieve the parameters of the
staircases.  Indicate the vertices of the solid.  The system will display the
rise and tread dimensions and the result of the (2h+b) formula.
