Change Floor and Ceiling Heights.

HOW TO:

		Change Floor and Ceiling Heights
		================================
		
Since levels are a little dull without things like stairs, cliffs, low tunnels etc., you will
no doubt want to alter the default floor and ceiling heights of your level. Here is how you do it:

1. Overview
-----------

	The floor and ceiling height changing routines work on a 'clipboard' principle. The height
	of a floor or ceiling is read into the clipboard by clicking with the RIGHT mouse button on
	a zone. The height in the clipboard can then be changed and pasted back into the zone, or
	as many zones as you wish, by clicking within them with the LEFT mouse button. This allows
	you to speedily change the floor or ceiling heights of many zones.
	
	There are four heights which can be changed in each zone. These are:
	
		Upper Roof Height
		Upper Floor Height
		Lower Roof Height
		Lower Floor Height
		
	The icons to click on to edit each of the above are arranged on the top row of the icon bar
	in the level editor, starting on the fourth icon from the left. Remember, the icon bar can be
	scrolled left and right using '(' and ')' on the keypad.
	
	Normally, only the Lower Roof and Lower Floor heights are defined. The other two are initialised
	to 5000, meaning 'DO NOT USE'. The Upper Floor and Roof heights are used in the definition of
	gantries or two-storey rooms (see below).
	
	NB: VERY VERY VERY IMPORTANT! In AB3DII, heights are measured DOWNWARDS! This means that a height
	    of -16 is HIGHER UP than a height of 0, which is HIGHER UP than a height of 16. 
	    
	NB: VERY IMPORTANT: Floor and ceiling heights are measured as absolute values. The floor is not
	    measured by its distance from the ceiling, and neither is the ceiling measured by its distance
	    from the floor. If the floor height in a room is 128, and the ceiling height is 64, then the
	    height of the room is 128-64=64.
	    
	Rooms default to being 128 high, with the floor at 0 and the roof at -128.
		
2. General Usage
----------------

	Click on the icon corresponding to the value you wish to change. If you wish to grab the
	corresponding height of a zone, click in that zone with the RIGHT mouse button.
	
	Use the + and - keys to alter the height in the clipboard. Holding RSHIFT down allows you
	to change them in increments of 8 rather than increments of 1. Note that due to a bug, either
	in AMOS or the keyboard hardware itself, you cannot hold down RSHIFT and + on the keypad to
	make the key auto-repeat (e.g. if you want to change a height by a great deal). If you wish to
	autorepeat, press RSHIFT and the + key on the main keyboard.
	
	When the desired height has been achieved, click with the LEFT mouse button in any zones whose
	height you wish to set to the new value.
	
	Heights can be positive or negative, but REMEMBER that heights are measured DOWNWARDS!
	
3. Creating... Stairs
---------------------

	Usually, stairs go down in steps of 16. There's no reason you can't make them steeper or
	shallower than this, but 16 is a good value.
	
4. Creating... Gantries
-----------------------

	This is a feature unique to AB3D on the Amiga. It is possible to define overhead walkways or
	corridors for the player to use:
	
	
	UPPER roof height ->  ---------------- -------- <-- Roof height of neighbouring Zone
			 		      .
					      .
					      .
					      .
	UPPER floor height -> ________________.
	                     		      |              
	                     	SOLID	      |              
	                     	WALKWAY	      |              
	       Roof Height -> ________________|
			                      .
			                      .
			                      .
			                      .
	      Floor Height -> ---------------- -------- <-- Floor height of neighbouring zone

	
	This is a simple procedure for creating a gantry.
	
	1. Define the area in which the gantry is to be created. REMEMBER: Gantries can only be
	   built from ENTIRE ZONES. You CANNOT HAVE a big room made of a single zone, with a gantry
	   across it. You must have something like this:
	   
	   *--------*----*-------------------*
	   |        #    #                   |	      
	   |        #    #                   |	      
	   |   A    # B  #        C          |	      
	   |        #    #                   |	      
	   |        #    #                   |	      
	   *--------*----*-------------------*
	   
	   If you want to be able to see both under and over the gantry in zone B, ensure the floor
	   and ceiling heights of zones A and C are far enough apart (about 256 apart is adequate).
	   Now, select 'DEFINE ROOF HEIGHT'. Click with the RIGHT mouse button on zone A, to grab the
	   height.
	   Now select 'DEFINE UPPER ROOF HEIGHT'. Click ONLY in zone B with the LEFT mouse button. The
	   Roof height from zone A will be copied into the Upper roof height of zone B.
	   Repeat the above, but with the Floor Height of zone A and the Floor height (not the UPPER
	   floor height) of Zone B.
	   
	   You have now defined the upper ceiling and lower floor heights of B. It remains to define the
	   in-between values to describe the walkway.
	   
	   You should still have the Floor height of A in the clipboard. Click on 'DEFINE UPPER FLOOR
	   HEIGHT' and then adjust the value upwards using 'RSHIFT -' until it is about 128 above
	   the floor height. Click with the LEFT mouse button in zone B. This defines the upper surface
	   of the walkway.
	   
	   Select 'DEFINE UPPER ROOF HEIGHT' and click in zone B with the RIGHT mouse button. Select
	   'DEFINE ROOF HEIGHT' and adjust the value to something slightly further down than the upper 
	   floor value you just defined. A difference of 8 is a very thin walkway; greater differences
	   mean greater thicknesses of gantry.
	   
	   There is no reason why the floor height and upper roof height of B should be the same as the
	   floor and roof heights of A and C, so feel free to change any of them to create any
	   setup you wish. For example, the following yields a pair of corridors which cross but
	   are invisible from one another:
	   
	   		___________________
	   		|                 |
	   		|                 |
	   		|                 |
	   		|     UPPER B     |
	   		|                 |
	   		|                 |
	   		|_________________|
			.                 .
			.                 .
	_____________________________________________________
			.                 .
			.                 .
			.                 .
		A	.     LOWER B     .         C
			.                 .
			.                 .
			.                 .
	_____________________________________________________
	
	   You can put gantries in as many zones as you wish, even ones next to each other, which allows
	   for all sorts of nice effects, eg:
	   
	   Floating platforms
	   Two storey rooms with a connecting hole or lift or flight of stairs.
	   Bridges over water
	   Multi-level staircases (tricky but possible; check out level 11 of the first AB3D)