L Systems : Creating Plants from Simple Rules - Computerphile

From simple rules, complex 'organisms' can emerge. PhD candidate Zachariah Garby has been studying the papers to find out what it's all about.
This was formerly called: Digital Plants (L-Systems)
EXTRA BITS: • EXTRA BITS - More on L...
Zac's code: bit.ly/C_Zac_L-systems
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This video was filmed and edited by Sean Riley.
Computer Science at the University of Nottingham: bit.ly/nottscomputer
Computerphile is a sister project to Brady Haran's Numberphile. More at www.bradyharanblog.com
Thank you to Jane Street for their support of this channel. Learn more: www.janestreet.com

[@georgetownsend1479]

Props to the presenter for breaking down L systems in such an accessible way - he did a great job explaining the concept and its applications. Super interesting stuff!

[@raedev]

I have been waiting for more procedural generation-centric computerphile videos for like 10 years, glad to see something so actively close to it! making things out of randomnes and simple rules is so fun, it's why it's my specialty when it comes to programming: it's just so much fun to tweak one value and see something completely different, but very much of the same type, all coming from *pure randomness*.

[@vincei4252]

I have a copy of "The Algorithmic Beauty of Plants" by Przemyslaw Prusinkiewicz and Aristid Lindenmayer. It was my introduction to L-Systems. It's a prize book in my collection of esoteric books. [edit] I just checked and found a PDF copy on the Internet Archive.

[@dertythegrower]

See... sometimes youtuber comments are actually a educational gold mine... things like that have molded how I see the world better, sometimes aiding me see ahead of future markets. Cheers.

[@vincei4252]

@@dertythegrower Sadly I had to check that my comment wasn't deleted/hidden by the overlords who's aim seems to be preventing the dissemination of information unless it's curated by them.

[@rdf256]

That book is underrated. It led me to write L-system parsers in Perl back in the day, Perl being well suited for such things (and not much else 😉).

[@andrewharrison8436]

That's strangely satisfying. I thought "Cow Parsley" quite early on but the final drawing was beyond my expectation.

[@0x1F9F1]

The first of hopefully many videos from Zac "Monad" Garby!

[@zacgarby3113]

So you know how L-systems form a monad…..

[@leobattle9489]

PhD candidate Zachariah Garby 🗣🔥

[@theloremaster9544]

This is a very cool subject! One time I booped Zac’s snoot with a medieval bopper. The lil scratchy is part of my legacy and you can see it on his nose in this video

[@fiskebent]

Great presentation. It reminded me of some of the (non-plant) fractal curves that can be generated by line segment substitution. Like the Hilbert curve and Koch curve.

[@dkgndianko]

This reminds me the project we had in Algorithms at the end of the second semester my first year at university. It was amazing to draw L-system simulations using Pascal programming language.

[@GilesBathgate]

Seems like plants are Turing complete. Next question, does it run doom?

[@neilbru]

And then, as is tradition, "But can it run Crysis?"

[@harriehausenman8623]

Great topic well presented! Please more about L-Systems, grammars and generalisations of it! 🤗

[@yaseminyilmaz1648]

There goes my hero

[@rachel_rexxx]

One of discrete math's real world applications (in biology). Neat.

[@paxdriver]

Brilliant!

[@mulad]

Reminds me of playing around with tree shapes in Fractint back in the '90s

[@Meuszik]

Great video!

[@user-eu2bd6ht1q]

I ❤ ZMG and I ❤ Cow Parsley. Want more of him

[@yaseminyilmaz1648]

The cows year for Zac Garby

[@sanamorii]

garby sweep

[@kaushaltimilsina7727]

These "formal rewrite systems", is what they have been working on at Wolfram Physics Project.

[@dragolov]

Respect!

[@GeoffryGifari]

Could this link to cell signaling during development?

[@LegendHD]

спасибо

[@markjfannon]

the king

[@flamingpi2245]

We just learned about L systems in a programming class

[@edupe6185]

This guy seems so nice!

[@amywyvern3924]

Thanks for the video. That reminds me the I first time I coded a tree shape in LOGO 🐢 (memories). It made me want to learn more about fractals and programming languages.

[@YuTv1408]

Maybe thats why San Jose is called The Silicon Valley. . Not the Bilogy Valley. But you preffer to have cells versus electrons in your iphones. I guess Biology is greater than materials science also right.

[@dru6809]

Very cool

[@markwilliams2192]

zac garby 🔛🔝 fp lab sweep

[@GeoffryGifari]

Is this process reversible?

[@play005517]

it remindes me of parsing and an EBNF grammar looks like an L-system.

[@ishanbhatt6067]

Lovely

[@NocturnalJin]

I didn't think we were allowed to say KACBCAK on KZbin.

[@orcu]

Yeah, it is about growing plants. Jokes aside L-Systems were available in very early Houdini versions and were used for plant generation in movies

[@lilb07]

Is this related to fractal geometry?

[@yesterdaysrose5446]

It's at very least in the same vein of iterative generation techniques. I'm pretty sure L-systems were included in the fractal generator I used back in the day (Fractint, I think?)

[@zacgarby3113]

It totally is, yeah. These trees are fractal in nature, and you can also generate your standard fractals (Hilbert curves, Sierpinski striangles, etc etc) using L-systems. I've got some nice examples of this in the code listed in the description if you're interested.

[@MichaelPiz]

Read _A New Kind of Science_ by Stephen Wolfram. He takes simple recursive "machines" like this to amazing places, including considering whether nature actually implements such rules.

[@Amonimus]

These shapes can get quite complicated, but the rules are simple, so it's not unlikely seed/fetus cells work this way.

[@PrinceBrosnan]

🌷

[@FrohnJusciante]

So A=B and C=D? Why not using the same name or am I missing something? Great video though

[@zacgarby3113]

Thank you! While A and B are rendered in the same way, they map to different sequences, so play different structural/developmental roles.

[@bertblankenstein3738]

The amoeba logo and L instantly made me think Debian Linux.

[@mp_rho]

looks just like grammars up until you start associating characters with little drawings

[@zacgarby3113]

Yup! They're essentially context-free grammars except you make all rule substitutions simultaneously.

[@saiello2061]

I now know what L-Systems are about 😁.

[@nicksamek12]

14:20 reminds me of arabidopsis

[@MusicMadtm]

leaves are cool but phd candidate zachariah garby is cooler

[@theanttman]

Ummm... where is the brown paper?

[@AlexPinkney]

Wrong channel

[@MazinManCW]

Took an L system last night in twisted towers

[@yash1152]

3:59 so, we in greek now? alp, bet, 'c', del, kap ?

[@plutoh28]

more like a W system

[@recklessroges]

Looks exactly like cow-parsley.

[@MatthewatCourseCareers]

Hey Computerphile - We sent you an email about a paid partnership. Let me know what you think.

[@ptousig]

Your clock is broken.

[@ethangold4900]

L-systems? More like W-systems

[@Monothefox]

Sponsored by Office Depot.

[@monkeybarmonkeyman]

So funny... who makes the rules eh?

[@dertythegrower]

Pi does.

[@dertythegrower]

Bacteria and the shape of seashells (relates to Pi)

[@pyroMaximilian]

The oddly-skewed, perspective-corrected segments were painful for me to watch. May I humbly ask that you kindly forgo that effect in future videos? Thank you.

[@jacobgarby199]

first

[@YuTv1408]

Biology is walk in the park compared to computer science. Anyone can regurgitate information. Few can interpret and really understand it.( like math, physics, cs and engineering).

[@jacobgarby199]

what are you on about

[@PRIMARYATIAS]

Check computational biology and you will see how far more complex biology is compared to Math, CS, EE, ME,etc… (research in this field actually fuses those disciplines together).

[@yaseminyilmaz1648]

Goofy take

[@mp_rho]

should've ended with "Biology is walk in the park compared to computer science." the statement was true up until this point. in a literal sense.

[@YuTv1408]

NPC_morons get upset when you tell the truth hu? Computational Biology is No Longer just Biology. NOTHING IS HARDER THAN Math or Physics people!!!