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Algorithmic Botany

algorithmicbotany.org

172 pointsthe-mitr24 comments

Lindenmayer's work is absolutely wonderful.

Although L-systems are ruthlessly simple, sometimes they are a little unintuitive, because the rewrite rules are in string space, not physical space. A couple of months ago I wrote http://canonical.org/~kragen/sw/dev3/skitch#!rrrrrrrrfffffff...] which I think might be a promising alternative that's maybe easier to understand, although it's less powerful. I haven't figured out how to get a dragon curve out of it yet, but I think it's possible.

If you like L-systems you will almost certainly like https://contextfreeart.org/ as well.

Wow, that's a fun tool! Very enjoyable to play with. Thank you for making it.

You're very welcome!

Here's a Heighway dragon (it follows the same idea as your Koch snowflake). It could be shorter if 45 degree turns were possible.

    rrr@4[a rrr rrr rrr [c@0.5a]f rrr [d@0.5[b cf rrr df rrr rrr rrr cf rrr rrr rrr df rrr]]f rrr cf rrr rrr rrr df]

http://canonical.org/~kragen/sw/dev3/skitch#!rrr@4[a_rrr_rrr...]

and a Lévy dragon rrrrrrrrr@3.5[a rrr rrr rrr [b@0.5a]f rrr bf bf rrr bf]

Wow, that's wonderful! The Lévy dragon, like the Koch snowflake, shows one of the weaknesses of the system; I was thinking of adding G to go forward without leaving a trace and /3 to divide the turn angle by 3 (for any value of 3, including negative values).

Beauty is in the eye of the beholder: Relish the delightful Chicago accent and attitude of Crime Pays but Botany Doesn't, presenting The Filthiest Flower in All the Land, Clitoria:

https://www.youtube.com/watch?v=wCyzQMFb60Y&ab_channel=Crime...

All his stuff is just as fascinating, entertaining, and educational -- check out his channel! His videos about carnivorous plants are a trip, too. The money shot and pigmy assed sundew starts at 4:20:

(#182) A Strange Carnivore Called Cephalotus folicularis

https://www.youtube.com/watch?v=vBvntuxAL-Q&ab_channel=Crime...

A botanical tour of beautiful West Oakland, California, across the train tracks and under the superhighways:

(#195) The Plant Ecology of Concrete, Garbage and Urine - Botanizing A Toilet

https://www.youtube.com/watch?v=35qF2hEefXg&ab_channel=Crime...

>WARNING : THIS EPISODE SHOWS IMAGES THAT ARE AN UTTER BUMMER. Thin-skinned, easily-upset viewers will want to pass.

>Botanizing a Toilet :

>The bleak barren wasteland of neglected urban infrastructure serves as an example of an ecological phenomenon known as "primary succession", however the cast includes a patchwork of non-native species from all over the globe. What plant species are able to thrive amidst the homeless camps, human bleakness (wealth disparity 101), garbage and concrete? Join CPBBD as we explore the ecology of garbage, concrete and urine.

The Ethnomycology of Ugly Landscaping:

https://www.youtube.com/watch?v=RHRgY8fZNv4&ab_channel=Crime...

>Join us as we explore the affinity that a species of psychoactive mushroom seems to have for the mulch beds of ugly landscaping in otherwise bleak metropolitan settings such as luxury condominiums, banks, strip malls, traffic medians, etc.

I have to second this recommendation and add my favorite video[0] of his, "Kick Me In The Asteraceae, with Helianthus annuus," about sunflowers. It's truly an informative and down to earth take on what can be a very stuffy and jargon-dense subject.

[0]: https://www.youtube.com/watch?v=D44YgtQraXY

I remember having Prof. PRUSINKIEWICZ at the UofC giving lectures about physical modeling and animation: one of the most passionate and interesting course I have attended!

I enjoyed his computer graphics course so much that I did a master's under his supervision.

Stochastic rules allow very natural looking trees. Most L-System implementations don't allow choosing rules with probability.

I have been able to make somewhat realistic looking trees so far. http://xosh.org/Stochastic-L-System/ (WIP)

I am hoping to make many different kind of trees/plants. Can make palm tree with it. Haven't figured out pine tree yet

There are some nice pines in http://marief.soler.free.fr/Monsite/lsystem0_en_css.htm and http://paulbourke.net/fractals/lsys/.

Professor Prusinkiewicz belongs to a generation of Polish Engineers/Computer scientists who greatly expanded on the work of their predecessors who in turn had to essentially restart the education system after WW2.

Much of the syllabus for undergraduate courses was written by these people, who continued contributing well into retirement. I daresay the tech landscape in this country today would be very different without them.

I once used 'The Algorithmic Beauty of Plants' (http://algorithmicbotany.org/papers/#abop) to build a simple L-System web service while studying: https://lsystems.raphaelpour.de/

There is a cool algorithm called space colonization that can do a lot of what l-systems do (such as tree modeling). Pretty straightforward to implement and has some nice results.

http://algorithmicbotany.org/papers/colonization.egwnp2007.l...

For the curious: I've written a basic space colonisation algorithm to simulate leaf venation patterns in a browser here: https://openprocessing.org/sketch/1211361

(note: I wrote this many years ago and it's horribly inefficient, I don't even dare to look at the code anymore, but it's on that same page)

Uh, not sure what I did exactly, but this is really cool: https://i.imgur.com/6wDRXMd.png

You can do pretty impressive stuff by just tweaking random knobs. I'd recommend playing with the angle and iteration setting. But be patient with the iteration one. The computing complexity rises exponential with increasing iterations which causes the tab to freeze..

EDIT: Fix typo and improve iteration explaination

Looks like a relative of the Gosper curve! https://en.wikipedia.org/wiki/Gosper_curve

Wow, good catch! I'm highly impressed!

L-systems are a lot of fun. When messing around with pen plotters a few years ago with a friend, we implemented an L-system driven plotter and one of the more interesting programs we found to run on it was an aperiodic Penrose tiling. We ended up throwing a party with the plotter going and art supplies so folks could grab a copy and color them in. Some videos below of the plotter in action.

https://www.instagram.com/p/Bfp0hATFzfm/?taken-by=dannysaza

https://www.instagram.com/p/BgS4MkeDEt0/?taken-by=dannysaza

Aaaand it's gone. The front page of HN is a bit rough on smaller web servers.

I read 'The Algorithmic Beauty of Plants' a bunch of times, even implemented some of the algorithms in Java (although I mostly just used recursion rather than L-systems). Must get back into that.

Huzzah! I was looking for algorithms that organically grow meshes last week and couldn't find anything past the flood of generating approximate trees for games. This is a great resource.

Related recent discussion for anyone who missed it:

The Algorithmic Beauty of Plants: https://news.ycombinator.com/item?id=27240927

Botany Bay... Botany Bay??! Oh no...

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