Here's some info about using the BUILD editor dated September 1995 to
make Duke3D levels:

General:
--------

Keypad Enter - Toggle 2D/3D mode

2D mode:
--------

ESC          - File options:
               N - New Level
               L - Load Level
               S - Save Level
               A - Save As Level
               Q - Quit


R-mousedrag  - Scroll map
L-mousedrag  - Drag point

Space        - Start vertex drawing. Hit space for every point and stop by
               ending at the start point

Ins          - Insert point
Del          - Delete sprite. I haven't figured out how to delete points yet

S            - Insert sprite
Tab          - Show sector info
Shift-Tab    - Show sprite/wall info

A/Z          - Zoom in/out
G            - Change grid size
L            - Toggle lock to grid

Right shift  - Drag mouse to select multiple things. You can then move them

Scroll-lock  - Set player start position

</>          - Strafe / Rotate sprite object

F1-F4,F9,F10 - Fine tune the angle, x and y position

J            - Joins two sectors

Alt-F        - Makes the wall hightlighted first wall of sector

Ctrl-T       - Show flags on-off

The functions of these are unknown:
t - sector lo-tag
h - sector hi-tag
c - does something with the walls er sides
f5 - gives sector number, and displays font
f6 - gives wall number
f7 - nick's sector variable     
f8 - nick's wall variable      
                                      

3D mode:
--------

You select target by positioning the mouse cursor on it.

arrows         - Move around

Left shift     - Run
A/Z            - Jump/crouch (press caps-lock to MOVE up/down)

S              - Insert sprite
R              - Rotate sprite            |
</>            - Rotate texture/sprite    | Try both and you will see the
                                          | difference
T              - Set transparent sprite

[/]            - Slant floor/ceiling from the first wall of the sector
                 (use Alt-F in 2D)

pgup/pgdn      - Move floor/ceiling or sprite up/down
shift-pgup/pgdn- Move floor/ceiling or sprite up/down in finer steps

8,2,4,6      - Stretch texture horizontally/vertically (keypad)
Shift-8,2,4,6- Align textures  (keypad)

V              - Select sprite/wall texture. Press twice to see full list
E              - Toggle texture density (1x, 2x)

+/-            - Increase/Decrease the lightning (keypad)

That's all commands that I know of. Please let me know if you have any
further. Good luck with your map making!

Anders Korsvall
korsvall@lysator.liu.se