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1993-05-17
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1,009 lines
3DEDIT
BETA-VERSION 0.8
IF YOU HAVE ANY QUESTIONS,SUGGESTIONS,CRITISM OR
SOMETHING ELSE YOU MIGHT WANT TO SAY ABOUT
3DEDIT, YOU MAY REACH US AT
INTERNET: ERIK-TAM@SATURN.DSV.SU.SE
MAIL: HUMAN SOFTWARE BRÖTV.42 161 39 BROMMA
SWEDEN
PLEASE LET US NOW YOUR OPINION.
A REAL MANUAL WILL BE RELEASED WITH THE NON-BETA
VERSION. THIS DOCUMENT IS REWRITTEN AND
ENLARGED ALL OF THE TIME CONTACT US FOR THE
LATEST VERSION.
-1-
CONTENTS
1.BEFORE YOU START. . . . . . . . 3
A. What do I need?. . . . . . . . 3
B. What is 3dedit?. . . . . . . . 3
2.3D-GRAPHICS A SHORT INTRODUCTION . . 3
A.What is an object made of . . . . 3
B.Points . . . . . . . . 3
C.Polygons . . . . . . . . 3
D.Hidden faces . . . . . . . 4
E.Depth Sortint . . . . . . . 4
F.What do I read to learn more? . . . 4
3.VIEWING THE BOAT A SMALL INTRODUCTION . 5
A.Starting 3dedit and loading the boat . 5
B.The screen . . . . . . . 5
B.The buttons . . . . . . . 5
C.Moving the boat . . . . . . 5
D.Rotating the boat . . . . . . 6
E.Leaving 3DEDIT . . . . . . 6
3.CREATING A BOX-A QUICK START . . . 6
A.Starting 3dedit . . . . . . 6
B.Show points . . . . . . . 6
C.The first point . . . . . . 6
D.Moving the point . . . . . . 7
E.Creating a new point . . . . . 7
F.To change an AS to another point . . 7
G.To create a polygon . . . . . 7
h.Changing the view . . . . . . 8
i.The backside of the box . . . . 8
j.Creating the rest of the cube . . . 9
5.CREATING AN OBJECT . . . . . 9
A.Creating points . . . . . . 9
B.Moving points . . . . . . . 9
C.Selecting points . . . . . . 9
D.Destroying points . . . . . . 9
E.Viewing all points . . . . . 10
F.Creating a polygon . . . . . 10
G.Selecting a color . . . . . . 10
H.Selecting a shape . . . . . . 10
I.No backface - Clockwise order . . . 11
J.Back-face polygons . . . . . 11
K.Destroying a polygon . . . . . 11
4.THE PANEL AND THE BUTTONS . . . . 7
6.LEGAL STUFF . . . . . . .
-2-
-BEFORE YOU START-
WHAT DO I NEED?
You need an 100% IBM-compatiable PC with a 286 processor or
higher with VGA-card and a mouse. Note that the VGA-card
must be truly register compatible with the orginal VGA-card
from IBM.
WHAT IS 3DEDIT?
3dedit is an application designed to make 3ddesign easy and
smooth. 3dedit uses polygon-based graphics, which means
that each object is made of colorfilled polygons. You've
probably seen it in flight simulators etc. 3dedit is a part
of the polyworld package, which is a C-library together with
tools, made to make true 3d-graphics available to the
C-programmer. A Turbo Pascal version may appear later.
3dedit creates and saves objects in a format that G3DLIB can
use. Create your own F15, Driving game etc.
3D-GRAPHICS A SHORT INTRODUCTION
If you have some knowledge about 3d-graphics, you might skip
this part. 3D graphics is in short, to manipulate a model
of a 3dimensional object, or group of objects, and view it
on a 2dimensional screen. At least, thats whats we are
concerned with. In this context we will call an model of an
3d-object just 'OBJECT'.
WHAT IS AN OBJECT MADE OF
An object in 3dedit is defined by points and polygons. Each
polygon is defined by a number of points in the object.
This is easier than it sounds, you just have to look at a
regular flight simulator to know what I mean. For an
example, a box is defined by its eigth corners(the points)
and its six sides(the polygons).
POINTS
A point is located in the 3dspace by its coordinates along
the three axis, X-Y-Z. The Z-axis is the axis thats goes
'into' the screen. In 3dedit, you never have to be concerd
with the actual coordinates of a point.
POLYGONS
The polygons are defined by points. In 3dedit you use 2
types of polyons, triangles and quadron(with 4 corners). A
-3-
face of an object can be made up of many polygons.
HIDDEN FACES
When you view an 3demonsional object, all faces are never
seen at the same time. If you take an box, you can at most
see three faces of it at one time. This is quite important
in 3d-graphics, because the computer has to know when to
show a face or not. 3dedit uses a techinque called backface
culling to evaluate which polygons to show and which to
hide. To let 3dedit know this, certain steps must be taken
when you create an polygon.
DEPTH SORTING
Since the polygons in an object often overlap each other
when the object is displayed, the polygons have to be sorted
in order according to the distance from the viewer, before
they are drawn. After that, they are drawn in reverse
order, beginning with the ones that's most far from the
viewer. This is called the painters algoritm. The trouble
is that you must choose a point to use as the basis of the
sorting. In 3d3dit you have 3 different sort-modes that you
have to decide which to use for each polygon. This may
sound a bit complicated but trying the different modes
should make you get it.