CgTalk Maxscript Challenge 016: “L-Systems!”
DESCRIPTION: Create a tool that utilises an L-System. This could involve creeping vines, trees, spiderwebs, city creators, anything! As long as you can think of a creative way to utilise an L-System it's fair game.
[b]DEADLINE: 03/04/2007[/b]
RULES:
[ul]
[li]NEW RULE: Do NOT post your code until the deadline![/li][li]Code from scratch. Try not to use pre-exisitng functions or plugins.[/li][li]Show your script references, if any (eg. Looking at another script to assist you).[/li][li]You are encouraged to ask for help where needed, but try to do it on your own. The maxscript reference is an invaluable resource.[/li][li]Post your final script inside [/li]“`
tags (located on your posting toolbar).
[li]Post all code into THIS thread.[/li][li]Post the max version you coded in, plus any maxscript extensions you used. (Thanks galagast!)[/li][li]Try to finish the challenge in a week. There is no definite time limit.[/li][/ul]NOTES: Here’s a link to get you started: http://en.wikipedia.org/wiki/L-system . hint: Start basic!!!
Just some notes on this while i’m trying to work it out myself.
One of the most basic L-Systems is the Lindenmayer Algae formula, where:
A = B
B = AB
(or the other way around…)
Which essentially means if you hit an A branch, make a B branch. A B branch splits into A and B branches, and so the thing keeps growing.
The problem I find comes with array management, as everytime you make a split, you have to increase your growing loop by two. It’s doing my head in a bit working out how to keep the nested loops working, as essentially what I have now is:
[Sketon code]
for i = 1 to growthSystem.Count do
(
for a = 1 to branchCount do
(
if growthSystem[i] = A then drawSpline(A)
if growthSystem[i] = B then drawSpline(B)
else -- "AB"
(
drawSpline(A)
drawSpline(B)
branchCount +=2
)
)
)
Obviously this is a little simplified, but I can’t seem to get my code beyond creating the actual system (the easy part!!). It’s been a while since i’ve coded like this, so all discussions are welcome.
Hey Erliaz, that’s a pretty cool challenge, not sure if I have time right now but maybe later. I think I would try something like this to deal with your problem:
allstuff = #(A,B)
dostuff = true
while dostuff do
(
for i in allstuff do
(
---here you do the stuff
append allstuff B
append allstuff AB
)
if somecondition do dostuff = false
)
CML
The Algorithmic Beauty of Plants can be downloaded here as PDF:
http://algorithmicbotany.org/papers/
I am sure you can find some code snippets in this great book.
Georg
Thanks Rivendale, that will probably do the trick!
Great stuff rdg! Thanks. Can you post that link over at the geometrical calculations thread? I’d do it, but I want you to have the kudos!
Hi there, first time participating in this challenges and I’m not much of a math guy but I’ve already did the scripting for two Koch systems and a Bracketed OL System.
I did a different aproach, first I’ve built the string sequence and after that I did it’s visual representation, it seemed more obvious doing that way at the time. I’ll leave here a portion of the code that might help you. I myself I’m having trouble now going into 3D representations, so if anyone already did something it would be nice to share. Cya.
n=0 -- Current iteration
seq="F"-- Axiom
-- Construct L-system string
for n=0 to spn_nmax.value do -- Being spn_nmax.value a spinner for user input on maximum iterations
(
seqtemp=""
for i=1 to seq.count do
(
case of
(
(seq[i]=="F"): -- Represents the predecessor
(
if n==0 then seqtemp=seq
else
(
seqtemp=seqtemp+"F+F-F-F+F" -- Represents the rule
)
)
(seq[i]=="+"): --This stays as is, +-, no rules implied here, they represent right and left turns
(
seqtemp=seqtemp+"+"
)
(seq[i]=="-"):
(
seqtemp=seqtemp+"-"
)
)
)
seq=seqtemp -- And there you go, you have all your sequence based on user choosen iterations
)
I’m having trouble now going into 3D representations
Idea:
After doing the replacement via recursive stringreplacement
we could parse the string letter by letter and point to a differnt function to build the visual representation.
Though I forgot that i token could be build of more than one letter like +F or -F.
Regex could help here, mabye.
Georg
This could be done via some kind of turtle code. Check out the Complexity blog: http://www.scriptable.com/blog/complexity/
He’s done a few versions with flash actionscript.
Here’s my progression so far. Right now I think I have the interpretation of the rule wrong, but it’s a start:
WARNING: Don’t increase the iteration value!!!
brAngle = 22.5
brLength= 5
tempLength = 0
START = "F"
rule="FF-[-F+F+F]+[+F-F-F]+FF+[+F-F-F]-[-F+F+F]"
--rule = "F+F--F+F"
anglePos = [0,0,0]
storePos = [0,0,0]
tempPos =[0,0,0]
endBranch = #(storePos)
fn calcLSystem ruleStr iter =
(
tempString = ruleStr
for i = 1 to iter do
(
ruleStrLength = ruleStr.count
for p = 1 to ruleStrLength do
(
if tempString[p] == "F" then ruleStr = replace ruleStr i 1 ruleStr
)
)
print ruleStr
ruleStr
)
fn newAngle ang =
(
theta = ang
phi = 90 - theta
x = cos(theta) * brLength
y = sin(theta) * brLength
z = sin(theta) * brLength * cos(phi)
[0,y,0]
)
newSpline = splineShape()
addNewSpline newSpline
addKnot newSpline 1 #smooth #curve storePos
storePos += [0,0,brLength]
addKnot newSpline 1 #smooth #curve (storePos )
--rule = calcLSystem rule 1
branchCount = endBranch.count
q = 0
while not (q == 24) do
(
q +=1
storePos = endBranch[q]
anglePos = [0,0,0]
for x = 1 to rule.count do
(
case rule[x] of
(
"-" : anglePos += newAngle (brAngle*-1) --calculate right
"+" : anglePos += newAngle (brAngle) --calculate left
"F" : ( --go forward
newSpline = splineShape()
addNewSpline newSpline
addKnot newSpline 1 #smooth #curve storePos
storePos += ([0,0,brLength] + anglePos)
addKnot newSpline 1 #smooth #curve (storePos )
brLength/= 1.1
)
"[" : ( --remember branching point
tempPos = storePos
tempLength = brLength
)
"]" : ( --go back to branching point
append endBranch storePos
--branchCount = endBranch.count
storePos = tempPos
brLength= tempLength
)
)
)
)
I wish I could participate in these challenges, but I’m not a worthy programmer. I applaude all your guys efforts. I wanted to show you guys a link to an article by a guy who created an ecosystem using proceedural means in houdini. This is an example of taking your guys l-system stuff to the extreme, and I hope it inspires someone out there.
http://www.highend3d.com/articles/references/Ecosystem-simulation-in-Houdini-28.html
Hey Stephen, thanks! And if you’re worried about not doing so well in the challenges, we do the occasional “Back to Basics” challenges which allow people just starting up in Maxscript time to experiment.
Here’s my stuff.
(
fn laine pointA pointB =
(
ss = SplineShape pos:pointA
addNewSpline ss
addKnot ss 1 #corner #line PointA
addKnot ss 1 #corner #line PointB
updateShape ss
ss
)
-- Koch variant which only uses right angles
rollout kochmain1 "Koch 1"
(
spinner spn_nmax "Iterations:" type:#integer range:[0,100,0] align:#center
spinner spn_angle "Angle:" type:#integer range:[1,180,90] align:#center
button btn_doit "Do it" align:#center
progressBar doit_prog "" align:#center
on btn_doit pressed do
(
-- L-System variable related declaration
seed(timestamp())
t_start=timestamp()
doit_prog.value=0
n=0 -- Current iteration
seq="F" -- Axiom
-- Construct L-system string
for n=0 to spn_nmax.value do
(
seqtemp=""
for i=1 to seq.count do
(
case of
(
(seq[i]=="F"):
(
if n==0 then seqtemp=seq
else
(
seqtemp=seqtemp+"F+F-F-F+F"
)
)
(seq[i]=="+"):
(
seqtemp=seqtemp+"+"
)
(seq[i]=="-"):
(
seqtemp=seqtemp+"-"
)
)
)
doit_prog.value = 100.*n/spn_nmax.value
seq=seqtemp
)
t_end=timestamp()
print ("L-System string took " + ((t_end - t_start) / 1000.0) as string + " seconds")
-- L-system constructed
--Begin visual representation of L-system
seed(timestamp())
t_start=timestamp()
doit_prog.value=0
suspendEditing() -- Disable Modify Panel to make creation faster
delete $Koch1_* --Delete previous Koch geometry
length=10
angle=spn_angle.value
roda_left=false
roda_right=false
lx=0 -- Last X Point
ly=0 -- Last Y Point
lz=0 -- Last Z Point
af=0 -- Angle Facing
for i=1 to seq.count do
(
case of
(
(seq[i]=="F"):
(
nx=lx+(length*cos(af))
ny=ly+(length*sin(af))
nz=lz
newshape=laine [lx,ly,lz] [nx,ny,nz]
select newshape
newshape.name=uniquename "Koch1_"
newshape.render_displayRenderMesh=true
newshape.wirecolor=white
lx=nx
ly=ny
lz=nz
roda_left=false
roda_right=false
)
(seq[i]=="+"):
(
af+=angle
roda_left=true;
)
(seq[i]=="-"):
(
af-=angle
roda_right=true
)
)
doit_prog.value = 100.*i/seq.count
)
resumeEditing() -- Enable Modify Panel
clearSelection()
max zoomext sel all
t_end=timestamp()
print ("L-System graphic took " + ((t_end - t_start) / 1000.0) as string + " seconds")
-- End visual representation of L-System
-- End Koch
)
)
-- Quadratic Koch island
rollout kochmain2 "Koch 2"
(
spinner spn_nmax "Iterations:" type:#integer range:[0,100,0] align:#center
spinner spn_angle "Angle:" type:#integer range:[1,180,90] align:#center
button btn_doit "Do it" align:#center
progressBar doit_prog "" align:#center
on btn_doit pressed do
(
-- L-System variable related declaration
seed(timestamp())
t_start=timestamp()
doit_prog.value=0
n=0 -- Current iteration
seq="F-F-F-F" -- Axiom
-- Construct L-system string
for n=0 to spn_nmax.value do
(
seqtemp=""
for i=1 to seq.count do
(
case of
(
(seq[i]=="F"):
(
if n==0 then seqtemp=seq
else
(
seqtemp=seqtemp+"F-F+F+FF-F-F+F"
)
)
(seq[i]=="+"):
(
seqtemp=seqtemp+"+"
)
(seq[i]=="-"):
(
seqtemp=seqtemp+"-"
)
)
)
doit_prog.value = 100.*n/spn_nmax.value
seq=seqtemp
)
t_end=timestamp()
print ("L-System string took " + ((t_end - t_start) / 1000.0) as string + " seconds")
-- L-system constructed
--Begin visual representation of L-system
seed(timestamp())
t_start=timestamp()
doit_prog.value=0
suspendEditing() -- Disable Modify Panel to make creation faster
delete $Koch2_* --Delete previous Koch geometry
length=10
angle=spn_angle.value
roda_left=false
roda_right=false
lx=0 -- Last X Point
ly=0 -- Last Y Point
lz=0 -- Last Z Point
af=0 -- Angle Facing
for i=1 to seq.count do
(
case of
(
(seq[i]=="F"):
(
nx=lx+(length*cos(af))
ny=ly+(length*sin(af))
nz=lz
newshape=laine [lx,ly,lz] [nx,ny,nz]
select newshape
newshape.name=uniquename "Koch2_"
newshape.render_displayRenderMesh=true
newshape.wirecolor=white
lx=nx
ly=ny
lz=nz
roda_left=false
roda_right=false
)
(seq[i]=="+"):
(
af+=angle
roda_left=true;
)
(seq[i]=="-"):
(
af-=angle
roda_right=true
)
)
doit_prog.value = 100.*i/seq.count
)
resumeEditing() -- Enable Modify Panel
clearSelection()
max zoomext sel all
t_end=timestamp()
print ("L-System graphic took " + ((t_end - t_start) / 1000.0) as string + " seconds")
-- End visual representation of L-System
-- End Koch
)
)
-- Bracketed OL System
rollout brackmain1 "Bracketed OL System 1"
(
spinner spn_nmax "Iterations:" type:#integer range:[0,100,0] align:#center
spinner spn_angle "Angle:" type:#integer range:[1,180,26] align:#center
button btn_doit "Do it" align:#center
progressBar doit_prog "" align:#center
on btn_doit pressed do
(
-- L-System variable related declaration
seed(timestamp())
t_start=timestamp()
doit_prog.value=0
n=0 -- Current iteration
seq="F" -- Axiom
-- Construct L-system string
for n=0 to spn_nmax.value do
(
seqtemp=""
for i=1 to seq.count do
(
case of
(
(seq[i]=="F"):
(
if n==0 then seqtemp=seq
else
(
seqtemp=seqtemp+"FF-[-F+F+F]+[+F-F-F]"
)
)
(seq[i]=="+"):
(
seqtemp=seqtemp+"+"
)
(seq[i]=="-"):
(
seqtemp=seqtemp+"-"
)
(seq[i]=="["):
(
seqtemp=seqtemp+"["
)
(seq[i]=="]"):
(
seqtemp=seqtemp+"]"
)
)
)
doit_prog.value = 100.*n/spn_nmax.value
seq=seqtemp
)
t_end=timestamp()
print ("L-System string took " + ((t_end - t_start) / 1000.0) as string + " seconds")
-- L-system constructed
--Begin visual representation of L-system
seed(timestamp())
t_start=timestamp()
doit_prog.value=0
suspendEditing() -- Disable Modify Panel to make creation faster
delete $Branch1_* --Delete previous Koch geometry
length=10
angle=spn_angle.value
roda_left=false
roda_right=false
lx=0 -- Last X Point
ly=0 -- Last Y Point
lz=0 -- Last Z Point
af=90 -- Angle Facing
stack_af=#()
stack_x=#()
stack_y=#()
stack_z=#()
for i=1 to seq.count do
(
case of
(
(seq[i]=="F"):
(
nx=lx+(length*cos(af))
ny=ly+(length*sin(af))
nz=lz
newshape=laine [lx,ly,lz] [nx,ny,nz]
select newshape
newshape.name=uniquename "Branch1_"
newshape.render_displayRenderMesh=true
newshape.wirecolor=white
lx=nx
ly=ny
lz=nz
roda_left=false
roda_right=false
)
(seq[i]=="+"):
(
af+=angle
roda_left=true;
)
(seq[i]=="-"):
(
af-=angle
roda_right=true
)
(seq[i]=="["):
(
append stack_af af
append stack_x lx
append stack_y ly
append stack_z lz
)
(seq[i]=="]"):
(
af=stack_af[stack_af.count]
lx=stack_x[stack_x.count]
ly=stack_y[stack_y.count]
lz=stack_z[stack_z.count]
deleteItem stack_af stack_af.count
deleteItem stack_x stack_x.count
deleteItem stack_y stack_y.count
deleteItem stack_z stack_z.count
)
)
doit_prog.value = 100.*i/seq.count
)
resumeEditing() -- Enable Modify Panel
clearSelection()
max zoomext sel all
t_end=timestamp()
print ("L-System graphic took " + ((t_end - t_start) / 1000.0) as string + " seconds")
-- End visual representation of L-System
-- End Koch
)
)
rollout aboutmain1 "About"
(
label lbl_label1 "by Artur Leão for CGTalk Maxscript Challenge" align:#center
hyperlink hl_hp "Artur Leão Portfolio" color:(color 0 0 255) address:"http://dimensao3.com/al" align:#center
)
try
(
closerolloutfloater lsystemsfloater
)
catch()
lsystemsfloater = NewRolloutFloater "L-Systems" 300 435
AddRollout kochmain1 lsystemsfloater
AddRollout kochmain2 lsystemsfloater
AddRollout brackmain1 lsystemsfloater
AddRollout aboutmain1 lsystemsfloater
)