Examples

Here is an example of creating a 3DS file from scratch, and writing it to output. In the snippet, pointarray is a n-by-3 numpy array listing vertex coordinates, and facearray is an m-by-3 listing of point indices making up a face.

from Dice3DS import dom3ds
import numpy

def output_model(facearray,pointarray,filename):

    n = len(pointarray)
    m = len(facearray)

    # First, add a fourth column to facearray for the face flags.
    # Dice3DS pretty much ignores these flags, but they're required by
    # the 3DS format.

    padfacearray = numpy.zeros((n,4),numpy.uint32)
    padfacearray[:,:3] = facearray
    padfacearray[:,3] = 7

    # Create a smoothing group array.  When the whole model is to be
    # smooth, it is appropriate to set the array to all ones.

    smoothing = numpy.ones(m,numpy.uint32)

    # Create an N_TRI_OBJECT, which is basically a big list of
    # triangles.  This object lists the vertices, faces, smoothing
    # groups, and the transformation matrix, which is set to identity.
    #
    # Note that you can initialize a 3DS chunk in one of two ways: by
    # passing keyword arguments to its constructor, or assigning
    # attributes.

    obj = dom3ds.N_TRI_OBJECT()
    obj.points = dom3ds.POINT_ARRAY(npoints=n,array=pointarray)
    obj.faces = dom3ds.FACE_ARRAY(nfaces=m,array=padfacearray)
    obj.faces.smoothing = dom3ds.SMOOTH_GROUP(array=smoothing)
    obj.matrix = dom3ds.MESH_MATRIX(array=numpy.identity(4,numpy.float32))

    # Create a named object.  Give it the name OBJECT, and set its
    # object to the N_TRI_OBJECT created above.

    nobj = dom3ds.NAMED_OBJECT(name="OBJECT",obj=obj)

    # Now, create the stuff that appears in every (or almost every)
    # 3DS file.

    dom = dom3ds.M3DMAGIC()
    dom.version = dom3ds.M3D_VERSION(number=3)
    dom.mdata = dom3ds.MDATA()
    dom.mdata.scale = dom3ds.MASTER_SCALE(value=1.0)
    dom.mdata.objects = [ nobj ]

    # Output the 3DS file

    dom3ds.write_3ds_file(filename,dom)

Scripts

Dice3DS provides is two scripts, dump3ds and view3ds:

• dump3ds dumps the a 3DS file to output in human-readable form.
• view3ds is a simple 3DS model viewer, requiring PyGame or Pyglet, PyOpenGL, and if the model has textures, Python Imaging Library.

Downloads

Dice3DS is licensed under a BSD-style license.

Version 0.11 is the most recent version, released 7 August 2010.

• ZIP Format
• TGZ Format

Version 0.10 is here.

• ZIP Format (0.10)
• TGZ Format (0.10)

If you do Subversion you can get the latest updates here:

• http://www.tamperedevidence.com/repository/dice3ds/trunk/dice3ds

Links

Here are links to the homepages of the libraries used by Dice3DS:

• Numpy
• Python Imaging Library
• PyOpenGL
• PyGame
• Pyglet

Here are some links to other libraries and information about the 3DS file format:

• lib3ds: an LGPLed 3DS file library written in C.
• A description of the 3DS file format

About the name

I originally was going to call it Utility3DS or Util3DS. (Lib3DS was taken, and Py3DS is just lame, as all Py* names are). However, Utility is a boring and aesthetically unpleasing name, and didn't sound right. (I couldn't call it 3DSUtil because it needed to be a legal Python symbol.

So, I decided to name it Dice3DS in honor the famous cliche "It slices, it dices!" Definitely cooler and more euphonic than Util3DS.

FCAP Minor Mode for Emacs

• Language: Emacs Lisp
• Platform: Emacs
• Licence: Public Domain

This is a minor mode for Emacs that automatically capitalizes in Fortran 77, without needing to resort to CAPS LOCK. Also, it conveniently doesn't capitalize inside strings and comments. I find it extremely helpful and never program in Fortran without it.

• Download fcap-mode.el

ftpupsync

• Language: Python 2.1
• Platform: Unix
• Licence: Public Domain

This is a small script that can synchronize an FTP directory tree with a directory tree on the local disk. It does this by maintaining a catalog of everything it believes is on the FTP server; and updating the catalog whenever it updates the files on the server.

In this way, you can have a mirror of (for example) your website on your local disk, and whenever you make a change to the local mirror, you can run this script to update the pages on your server. It will make and remove directories as needed, and upload and remove files as needed. Only the new and changed files are uploaded. Renaming a file in the local mirror will usually result in that file being renamed on the server.

Unfortunately, it only works in one direction: independently changing a file on the server will not cause it to be downloaded to your local mirror.

I put this script on my web page because I think people will find it useful. However, it has a lot of loose ends untied. There's no documentation; you'll have to read the source to figure out how to use it. It won't work on Windows as is, for it uses some Unix-specific calls, but it shouldn't be hard to modify it so that it will. Finally, there is no built-in way to create the catalog. You'll have to create the initial catalog yourself (maybe by modifying the script to just output a check file).

• Download ftpupsync.py

I still use this script to keep my static files up to date.

Documentation

cat horizon.sc pittsburgh.sc | ./banks

cat horizon.sc pittsburgh.sc | ./banks
cat mountains.sc bb.sc | ./banks
cat mountains.sc river.sc pyramids.sc | ./banks

./banks < /dev/null

Control  Description           Default Key
-------  --------------------- -----------
IT       Open throttle         XK_Page_Up
DT       Close throttle        XK_Page_Down
FD       Move stick forward    XK_Up
BK       Move stick back       XK_Down
LT       Move stick left       XK_Left
RT       Move stick right      XK_Right
CS       Center stick          XK_Enter

Screen Shots

Here we are flying towards Downtown Pittsburgh. We can see the Point, several buildings including the USX tower, and several bridges including the Smithfield Street bridge. We see three instruments near the bottom.

About the IOCCC Entry

IOCCC stands for "International Obfuscated C Code Contest." It is an quasi-annual contest to see who can write the most unreadable, unintelligible, unmanagable, but legal C program.

In the 1998 IOCCC, My flight simulator won the "Best of Show" prize. Here is the source code to the program:

#include                                     <math.h>
#include                                   <sys/time.h>
#include                                   <X11/Xlib.h>
#include                                  <X11/keysym.h>
                                          double L ,o ,P
                                         ,_=dt,T,Z,D=1,d,
                                         s[999],E,h= 8,I,
                                         J,K,w[999],M,m,O
                                        ,n[999],j=33e-3,i=
                                        1E3,r,t, u,v ,W,S=
                                        74.5,l=221,X=7.26,
                                        a,B,A=32.2,c, F,H;
                                        int N,q, C, y,p,U;
                                       Window z; char f[52]
                                    ; GC k; main(){ Display*e=
 XOpenDisplay( 0); z=RootWindow(e,0); for (XSetForeground(e,k=XCreateGC (e,z,0,0),BlackPixel(e,0))
; scanf("%lf%lf%lf",y +n,w+y, y+s)+1; y ++); XSelectInput(e,z= XCreateSimpleWindow(e,z,0,0,400,400,
0,0,WhitePixel(e,0) ),KeyPressMask); for(XMapWindow(e,z); ; T=sin(O)){ struct timeval G={ 0,dt*1e6}
; K= cos(j); N=1e4; M+= H*_; Z=D*K; F+=_*P; r=E*K; W=cos( O); m=K*W; H=K*T; O+=D*_*F/ K+d/K*E*_; B=
sin(j); a=B*T*D-E*W; XClearWindow(e,z); t=T*E+ D*B*W; j+=d*_*D-_*F*E; P=W*E*B-T*D; for (o+=(I=D*W+E
*T*B,E*d/K *B+v+B/K*F*D)*_; p<y; ){ T=p[s]+i; E=c-p[w]; D=n[p]-L; K=D*m-B*T-H*E; if(p [n]+w[ p]+p[s
]== 0|K <fabs(W=T*r-I*E +D*P) |fabs(D=t *D+Z *T-a *E)> K)N=1e4; else{ q=W/K *4E2+2e2; C= 2E2+4e2/ K
 *D; N-1E4&& XDrawLine(e ,z,k,N ,U,q,C); N=q; U=C; } ++p; } L+=_* (X*t +P*M+m*l); T=X*X+ l*l+M *M;
  XDrawString(e,z,k ,20,380,f,17); D=v/l*15; i+=(B *l-M*r -X*Z)*_; for(; XPending(e); u *=CS!=N){
                                   XEvent z; XNextEvent(e ,&z);
                                       ++*((N=XLookupKeysym
                                         (&z.xkey,0))-IT?
                                         N-LT? UP-N?& E:&
                                         J:& u: &h); --*(
                                         DN -N? N-DT ?N==
                                         RT?&u: & W:&h:&J
                                          ); } m=15*F/l;
                                          c+=(I=M/ l,l*H
                                          +I*M+a*X)*_; H
                                          =A*r+v*X-F*l+(
                                          E=.1+X*4.9/l,t
                                          =T*m/32-I*T/24
                                           )/S; K=F*M+(
                                           h* 1e4/l-(T+
                                           E*5*T*E)/3e2
                                           )/S-X*d-B*A;
                                           a=2.63 /l*d;
                                           X+=( d*l-T/S
                                            *(.19*E +a
                                            *.64+J/1e3
                                            )-M* v +A*
                                            Z)*_; l +=
                                            K *_; W=d;
                                            sprintf(f,
                                            "%5d  %3d"
                                            "%7d",p =l
                                           /1.7,(C=9E3+
                              O*57.3)%0550,(int)i); d+=T*(.45-14/l*
                             X-a*130-J* .14)*_/125e2+F*_*v; P=(T*(47
                             *I-m* 52+E*94 *D-t*.38+u*.21*E) /1e2+W*
                             179*v)/2312; select(p=0,0,0,0,&G); v-=(
                              W*F-T*(.63*m-I*.086+m*E*19-D*25-.11*u
                               )/107e2)*_; D=cos(o); E=sin(o); } }

Note that this program will not compile out-of-the-box. It requires certain compile-time parameters. The folloing script builds it on my Linux system:

#! /bin/sh
cc banks.c -o banks -DIT=XK_Page_Up -DDT=XK_Page_Down \
        -DUP=XK_Up -DDN=XK_Down -DLT=XK_Left -DRT=XK_Right \
        -DCS=XK_Return -Ddt=0.02 -lm -lX11 -L/usr/X11R6/lib

If you want to try this program, I suggest you download the 1998 IOCCC Winners Distribution.

One of the rules of the contest was that the program could not be longer than 1536 bytes (excluding spaces, tabs, newlines, semicolons, and braces). Needless to say, cramming a flight simulator into such a small file was fairly difficult. I will say that if it weren't for the wonderful property of orthogonal matrices, this flight simulator would not have been possible.

Sightings

The IOCCC Simulator appeared in a book, Calculated Bets by Steve Skiena.

Links

• The official International Obfuscated C Code Contest website

Downloads

I do not distribute this program myself. If you want it, you can download the 1998 IOCCC Winners Distribution. The distribution comes with a dozen or so other winning entries, all quite interesting programs.

Note that this is a source distribution, and you will have compile it to run it. I've tested it on some versions of Linux, AIX, Irix, and Sun.

IOCCC Flight Simulator source code is in the public domain; there are no copyright restrictions on it whatsoever. However, the winners distribution has been copyrighted by the IOCCC judges. See the hint files in the distribution for details.