Stars of Shareware: Raytrace & Morphing/SOS-RAYTRACE.ISO/programm/utility/dos/lparse/readme

Text File | 1993-07-22 | 14.1 KB | 345 lines

┌─────────┬────────────────────────────────┬───────────────────────────────┐
│ Name:   │ L-SYSTEM PARSER/MUTATOR        │ (C) RenderStar Technology BV. │
├─────────┼────────────────────────────────┼──────────┬───────┬────────────┤
│ Author: │ Laurens J. Lapre               │ Version: │  1.0  │ 1993-07-22 │
├─────────┴────────────────────────────────┴──────────┴───────┴────────────┤
│ RenderStar Technology BV, Keizersgracht 448                        │
│ 1016 GD Amsterdam, the Netherlands                                   │
│ Fax [phone]                                                    │
├─────────┬─────────────────────┬───────────────────┬──────────────────────┤
│ Email:  │ 2:283/203.8@fidonet │ 'Lj Lapre' PCGnet │                      │
└─────────┴─────────────────────┴───────────────────┴──────────────────────┘


Disclaimer
────────────────────────────────────────────────────────────────────────────
This software is free and may be freely distributed, but is copyrighted by
the company RenderStar Technology BV. This software is provided as is
without any guarantees. The author and company assume no liability for
damages, direct or consequential, which may result from the use of this
software. The 'lparser.exe' file may not be used as part of any commercial
package without the explicit written consent of the author or company.


General
────────────────────────────────────────────────────────────────────────────
An l-system is a rule like description of a 3d form. It contains
descriptions of parts and how they should be assembeld together. The program
reads a l-system description in and processes it into a 3d form which can
then be outputed in several formats, including DXF and POV.

The description is applied to itself a number of times (= recursion levels)
so fractal and recursive forms are very easy to describe in an l-system.
That's why they are used a lot for plants and natural looking organic forms.
By increasing the recursion level the form slowly 'grows' and becomes more
complex.

This implementation of a l-system parser also allows 'mutations' to take
place during the growing of the form. These mutations can change the form
slightly or quite dramaticly. This allows you to create a form once and then
create a whole series of forms all clearly 'descendant' from the original
l-system.

Too help people get started a lot of example l-systems and pov files have
been included.

The lparser.exe is a protected mode program using the royalty free
Rational dos-extender (dos4gw.exe) supplied with Watcom 9. It needs a
386/387 or 486 with 4meg ram.


Execute like this :
────────────────────────────────────────────────────────────────────────────
lparser [options] [name]

examples :

lparser -x rcylin -d lsys03.ls
lparser -v -t0.5 -u10 -i30000 -g lsys05
lparser spider

Name is an l-system file with the ls extension. It will standard generate a
RenderStar compatible 'output.vol' file. Which can be shown and rendered
directly in RenderStar with the command : rs2 l. The l.* files are
RenderStar support files.


Persistence of Vision (POV) output:
────────────────────────────────────────────────────────────────────────────
Part off the pov file is setup by the user and the output.pov file is then
attached to the user's file.

-v            make pov object file

Generates a pov file format description. Only the body part of the file is
generated with a series of a l_base objects and leafs as triangles. See the
'exam.pov' file for more explanation. One can change the object definition
of the l_base element used in the l-system form to any one of the valid pov
shapes as long as the shape can be scaled differently in all 3 directions.

-b            make pov blob file

Instead of outputting objects, postionend components are written to the
output.pov file. These can be used to create 'bloby' objects. See
'bloby.pov' for an example how to set this up. All triangles are skipped.

-B            make multiple pov blob files

Each color part of the final form is written into its own output??.pov file.
This allows you to have mutiple blob's each with its own color and material.
See 'mbloby.pov' for an example. All triangles are skipped. The b*.pov files
contain several different forms and setups done with pov's blob functions.

-c            output inc files instead of pov file

The output files will now have the 'inc' extension for easier including in
other pov files.


DXF output:
────────────────────────────────────────────────────────────────────────────
-d            make dxf file (use with '-x cube' for fast dxf file writing)

This creates AutoCad R12 polyline polyface meshes in dxf file format which
can be used in Acad and 3DS. It's a much more efficient format then the
3dface format. It uses blocks and inserts. The most efficient dxf file (in
size and write/load time) is generated with : lparser -x cube -d [name]. If
you read the file into Acad12 make sure you have a new (no prototype) drawing
since the file contains block definitions as well. The objects will have
color and layer attributes set. By changing all object color attributes to
BYLAYER one can use the layer overview for easy, by layer, color setting.

-3            make dxf file

This is a simple 3dface only dxf file format which will always work. It has
no blocks or inserts but can become very large.


Other options:
────────────────────────────────────────────────────────────────────────────
-t [num]      set minimum thickness

This allows you to set the minimum thickness a form will get during
recursive generation. It is to make sure the forms don't get too 'thin' to
be seen and render correctly. It's typicly around 0.5 to 1.0.

-u [num]      mutate [num] times

Mutate the l-system a number of times before starting the geometry generation
fase and write the mutated l-system to disc as the file 'mutation.ls'. By
re-using this file one can build mutation series of forms.

-r [num]      overrule recursion depth
-a [num]      overrule angle

Overrule these values on the commandline. They are also set in the l-system
file but they will not be used when an overrule option is used on the
commandline. One can 'open' a form by starting with a angle of zero and
increase it to the final angle. This makes nice animations. Doing the same
with the -r option will slowly 'grow' the form into its final shape.

-p [num]      limit polygons to [num]

Limit the total amount off polygons/objects outputed during the parsing of
the final l-system production. After mutation the form may have grown very
(VERY) large. The whole form could be inserted in each of its branches ! The
default limit is 200.000 polygons/objects.

-i [num]      limit string length to about [num]

Limit the length of the final production string. This is also a way of
limiting the size and generation time of a form. When certain mutations
occur the generating time can become very long. The -i option can limit this
time. Use like : lparser -p50000 -i30000 lsys00. The default string limit
is 500.000 chars. The program can handle final l-systems strings up to 1
million chars.

-x [name]       use name.vol as base form

Instead of a simple block a special object (*.vol) can be used as a base
element. Example forms are ball, cube, cone, cylin8 (with 8 faces), cylin16
(with 16 faces), rcylin (with rounded edges) and tube. This is for generating
vol or dxf files only. Try : lparser -x ball lsys00. The changing of the base
forms for pov output is done by the user in the pov headers. See *.pov for
examples.

-l            show final L-string

Prints the final l-system production to the screen. This is the final string
which is then interpreted into a 3d form.

-g            add ground plane

Adds a large ground plane (2 triangles) touching the lowest point of the
form. This is for easy shadow projection and horizon.


More info ...
────────────────────────────────────────────────────────────────────────────
The book 'Evolutionary Art and Computers' by S. Todd and W. Latham was used
to base the genetic 3d form mutation principles on. In here you'll find a lot
of interesting ideas on how to 'grow' and 'evolve' organic looking 3d forms
of your own.

The implemented l-system is based on the one described in the book : 'The
Algorithmic Beauty of Plants' by P. Prusinkiewicz and A. Lindenmayer (this
is where the 'L' from l-systems come form). If you want more information on
making your own l-systems you'll want to check out this book. A lot can be
done by changing the l-systems suplied with the parser and seeing for
yourself what changes in the final form.

For this you can use the the following l-system files:

From The Algorithmic Beauty of Plants:

bop00.ls          cordate leave     pag 123
bop01.ls          plant        pag 27
bop02.ls          bush        pag 26
bop03.ls          form in 2d    pag 25
bop04.ls          block form    pag 20
bop05.ls          fractal        pag 9

Fractals from FractInt:

fract00.ls        4 dragon curves
fract01.ls        space snake
fract02.ls        round triangle tiling
fract03.ls        pentagon tiling
fract04.ls        triangle tiling

Free form experiments:

lsys00.ls         lobster form
lsys01.ls            "    var 1
lsys02.ls            "    var 2
lsys03.ls            "    var 3
lsys04.ls            "    var 4
lsys05.ls         spiral bush
lsys06.ls         tree base
lsys07.ls         half circle
lsys08.ls            "    var 1
lsys09.ls         cello plant
lsys10.ls         circle form

Mutations:

mut00 - mut08      mutations of lsys00.ls
mut09 - mut14      mutations of spider.ls
mut15 - mut18      distant relatives of lsys02.ls

Spiral forms:

spiral00.ls       overview of spiral types
spiral01.ls       spiral form
spiral02.ls       spiral tree
spiral03.ls       large spiral plant var 1
spiral04.ls       large spiral plant var 2


Syntax
────────────────────────────────────────────────────────────────────────────
For those who are already familiar with l-systems, here are the commands and
their functions for this lparser's 'dialect'. All commands are 1 char only
and simpler then for most lparsers. This is to keep them from getting
'broken' by the mutation process and speeds up the parsing.

┌─────────────────────────────────────────────────────────────────────┐
│ Orientation commands                                                │
├─────────────────────────────────────────────────────────────────────┤
│ +    turn left around up vector                      │
│ -     turn right around up vectos                      │
│ &    pitch down around left vector                      │
│ ^    pitch up around left vector                      │
│ <    roll left around forward vector                      │
│ >    roll right around forward vector                  │
│ |    turn 180 deg around up vector                      │
│ %    roll 180 deg around forward vector                  │
├─────────────────────────────────────────────────────────────────────┤
│ Movement commands                       when {} active          │
├─────────────────────────────────────────────────────────────────────┤
│ F    move forward and draw full length    record vertex          │
│ f    move forward with full length         record vertex           │
│ g    move forward with full length         don't record vertex      │
│ Z    move forward and draw half length    record vertex          │
│ z    move forward with half length         record vertex          │
│ .    don't move                 record vertex            │
├─────────────────────────────────────────────────────────────────────┤
│ Structure commands                              │
├─────────────────────────────────────────────────────────────────────┤
│ [    push current state                          │
│ ]    pop current state                          │
│ {    start polygon shape                          │
│ }    end polygon shape                          │
├─────────────────────────────────────────────────────────────────────┤
│ Inc/Dec commands                              │
├─────────────────────────────────────────────────────────────────────┤
│ "    increment length                          │
│ '    decrement length                          │
│ ;    increment angle                              │
│ :    decrement angle                              │
│ ?    increment thickness                          │
│ !    decrement thickness                          │
├─────────────────────────────────────────────────────────────────────┤
│ Additional commands                              │
├─────────────────────────────────────────────────────────────────────┤
│ c    increment color index                          │
│ *    reset color, thickness, length and angle                      │
│ @    end of object                              │
└─────────────────────────────────────────────────────────────────────┘


This is an example of a simple form definition (spiral01.ls) :
────────────────────────────────────────────────────────────────────────────
20
10
100
a
a=Fs+;'a
s=[::c!!!!&&[b]^^^^[b]]
b=F!+F+;'b
@


This is an example of a complex form definition (spider.ls) :
────────────────────────────────────────────────────────────────────────────
#-------------------------------------- "Octo Spider"
#-------------------------------------- Header
15                    # recursion depth level
10                    # basic angle in degrees
60                    # starting thickness in % of length
C                    # axiom
.-------------------------------------- Creature
C=LABHT
.-------------------------------------- Body
B=[???????zZZZ]
.-------------------------------------- Arms
A=[zf&&&&&&&&&"""[pj>>>>>>>>>S]|[qj<<<<<<<<<S]]
p=Ft+:'p                # left
q=Ft-:'q                # right
j=;"j
.-------------------------------------- Claws
S=['''!!r%^^r]
r=[Z?Z?Zu]                # claw assembly
u=Z[co]!'^::u                # claw tooth
.-------------------------------------- Legs
L=[c">>>>[s]>>>>[s]>>>>[s]>>>[s]>>>>>>[s]>>>[s]>>>>[s]>>>>[s]]
s=+++li+++dccc??""FF            # down legs
l=Ft+:'l                # upper leg
d=FFF'd                    # lower leg
i=;i
.-------------------------------------- Head
H=["">>>>>>>>>&&&&&&??FFFF!![???h][???k]%^^[??k]]
k=[Z?Z?Za]                # jaw assembly
a=Z[co]!'a                # jaw
o=&&&&&&&&&!!!!!F            # teeth
h=[^^gcccc"Z][^^ecccc"Z]        # eyes
g=z!+z!+z!+z                # left eye
e=z!-z!-z!-z                # right eye
.-------------------------------------- Tail
T=[f---------??""""""mccccF]
m=Ft+;'m                # curl
t=['::c!!!&&[f<<<n]^^^^f>>>n]        # spikes
n=[c{--z++z++z--|--z++z++z}]        # leaf
.-------------------------------------- End
@                    # EOF marker