Phototaxis

The work and its context

Phototaxis is a 1,000-edition Art Blocks Playground series by Casey REAS on the V2 core contract 0xa7d8d9ef8d8ce8992df33d8b8cf4aebabd5bd270. The official collection page places it in Art Blocks 500 / Playground, prints a fixed edition of 1,000 unique artworks, and dates public release to 21 September 2021.¹ Indexed project metadata retrieved on 18 September 2026 records project ID 164, script type p5@1.0.0, license CC BY-NC 4.0, vertical name playground, heritage status ab500, and 1,000 of 1,000 invocations.² Atlas position is an index number, not the contract project ID.

The project description on Art Blocks is written in the first person. It names a simulated environment of simple machines after Valentino Braitenberg's 1984 book Vehicles, lists four machine kinds (Explorers, Aggressors, Lovers, and Cowards), and states that each line charts the history of one machine's movement. It also states that the core of this code was the foundation for REAS's MicroImage series dating to 2001, worked on in fits and starts, and further developed for Art Blocks in 2021. The same paragraph documents keyboard controls: P to play or pause, B for the big bang, 1 through 5 to change magnification, and L to reveal light locations.¹

REAS is a Los Angeles-based artist and co-creator of Processing. That biography is context for why a 2021 browser port of a twenty-year drawing system exists. It is not a substitute for the dated Phototaxis statement. The AB5D artist dossier summarizes the same lineage and lists the Medium note and a gray.reas.com project page as bibliography leads.³ This essay follows those leads to the originals rather than treating the dossier as primary testimony.

Conception and development

The contemporaneous artist statement is Casey REAS, "Notes on Phototaxis," dated 18 September 2021 and published on Medium on 20 September 2021, the day before the collection page's public-release calendar date.⁴ REAS writes that he began learning to code in 1999 to make drawings he could not make by hand, pursuing emergence as discussed in artificial-life research. He identifies the Path prints shown at bitforms in autumn 2001 and the Tissue software and prints shown there in winter 2002 as the first public gallery versions of the system. Each line, he writes, inscribes the history of one software organism; one color stands for each of four organism types; brightness falls when the organism moves slowly.⁴

The same note states that Phototaxis is further work on the original source for those Path and Tissue prints and software. The original code was written in C++, later ported to Processing (Java), and in 2021 developed over a few months then ported to p5.js to run in a browser. "The core of the 2001 code survives intact, but the parameters around it have been further refined as long-form generative art." The edition of 1,000 is described as a narrow set of potential variations expected to map the space well.⁴ A later studio page on reas.com places Phototaxis inside the MicroImage family and repeats the C++ to Processing to p5.js sequence, adding that each minted edition fixed one interpretation of the system at minting.⁵

Braitenberg is named as the conceptual source for the machines. REAS writes that the Tissue machines are analogous to Braitenberg's Vehicles 2 and 3: two software sensors and two software actuators. He quotes the distance calculation used to sense a stimulus. He also writes that behaviors in Phototaxis differ from the original 2002 Tissue software.⁴ That last sentence is an artist claim about difference, not a line-by-line comparison performed for this essay. The 2021 note is the brief for this slug. Later interviews about CENTURY or Pre-Process mention Phototaxis only as a prior Art Blocks title and are not used here as Phototaxis conception documents.³

How the work was constructed

The indexed record reports script type and version p5@1.0.0.² The full script was retrieved on 18 September 2026 from projects_metadata.script on https://artblocks-mainnet.hasura.app/v1/graphql, filtered by contract 0xa7d8d9ef8d8ce8992df33d8b8cf4aebabd5bd270 and project_id "164". The UTF-8 payload is 7308 bytes. SHA-256 of those exact bytes is 57a994d9131fbdc79941579e3097d64291fb90bbfd1def3fc847f5df23bcc997. The script was read in full and was not executed in a local sandbox. The Art Blocks generator executes it in the browser when the live-view URL is loaded.⁶

The program seeds a custom RND xorshift generator from parseInt(tokenData.hash.slice(0,16),16). setup() creates a canvas the size of the window, sets RGB color mode scaled to 1, and calls bang(). bang() rebuilds the world: zoom chosen from hash thresholds, two to seven light objects of class L, a line-count register that can be 50, 200, 400 or 800, machine breadth and nerve offsets, a linear-sensor flag, and a max-speed of 4, 8 or 12. createFacade() picks one of seven named color sets (cs1 through cs7) and paints the background from the first swatch. createMachines() instantiates class M walkers. draw() recenters, scales by zoom, calls idle() then display() on each machine, optionally draws lights, increments bangTime, and at 1000 calls noLoop() and sets pause true.⁶

That halt matches the artist note: the thumbnail represents the simulation after 1000 iterations.⁴ Interaction is implemented in keyTyped(), not inferred from the title. P toggles loop() / noLoop(). B calls bang() and resumes. Keys 1 to 5 call bang(), resume, and set _zoom to 0.66, 1, 2, 4 or 8. L toggles showLights and redraws if paused. There is no audio API in the inspected script.⁶

Published token features name Size, Speed, Lights, Facade, Sensors, Alignment, Population, and Magnification.⁶ Those labels are index traits, not string literals inside the minified artist program. What is stored on chain is the project script plus each token hash. Rendering still requires a browser and the generator shell that injects tokenData. The digest is of the current indexed body, which the project record marks locked. No Ethereum block was pinned.²

The mint

Several clocks have to be kept apart. Token 164000000, invocation 0, was minted on 18 September 2021 at 17:38:10 and is currently owned by 0x5151f4b48cee4f7dcb7714e7b4b836aa847bf4e8.⁶ The project record's activated_at is 20 September 2021 at 21:10:34. start_datetime is 21 September 2021 at 19:00:00.² Invocation 1 (token 164000001) was minted on 21 September 2021 at 19:16:16. Invocations 10, 20 and 684 followed at 19:35:21, 19:40:33 and 19:54:21 the same day. completed_at is 21 September 2021 at 19:55:22.²⁶ The collection page prints "Released on September 21, 2021" and "Fixed edition of 1,000 unique artworks."¹

Invocation 0 therefore predates activation by two days and public start_datetime by three. It is the natural candidate for an artist or administrative mint; contract event logs that would prove the minter role were not pulled. Public minting evidence in this sample begins with invocation 1, sixteen minutes after start_datetime. From start_datetime to completed_at is 55 minutes 22 seconds. That span covers the remaining 999 tokens only if no pause occurred and if start equaled purchaser availability. This essay does not convert that span into a sold-out-in-minutes claim.

Invocations and max_invocations both read 1,000 on 18 September 2026.² The Art Blocks project page for project 164 records sales notes: "10Ξ starting price, 0.5Ξ resting price, reduced every 5 minutes."⁷ That is an announced Dutch-auction schedule on a current project page, not a recovered primary-sale receipt for any specific token. Current secondary listings on the collection page are not a substitute for those historic increments. Who paid 10 ETH, who paid the rest, and whether the schedule changed mid-sale remain open.

Copyright and licensing

The project metadata field license is the exact string CC BY-NC 4.0. No separate link_to_license field was stored on the indexed record inspected for this essay.² The Creative Commons Attribution-NonCommercial 4.0 International deed at https://creativecommons.org/licenses/by-nc/4.0/ permits sharing and adaptation with attribution and forbids commercial use as defined in that deed.⁸ Whether REAS intended that standard deed, a variant, or only the short label is not independently documented in a project-linked instrument beyond the Art Blocks field. The operative public text identified for the label is the 4.0 deed.

Artwork rights are separate from source-code rights. The artist script is visible through the Art Blocks index and generator. Visibility is not a license to copy, fork, or reissue the program. No SPDX identifier or copyright header was present in the inspected script body.⁶ p5.js 1.0.0 is a third-party runtime with its own license; the artwork CC label does not relicense that library.

AB5D's CC0 grant covers this essay's original prose only. Token ownership by AB5D or anyone else does not transfer copyright in the images.

Close reading of examples

Four tokens were confirmed on the V2 contract and inspected as media-proxy PNGs (the 1000-iteration halt state described by the artist) with linked generator URLs. They follow the assignment discovery set: invocations 0, 1, 10 and 20. Invocation 684, owned by 0xdd19308a9731cdecb67e0d80ca6823394208c045 on 18 September 2026, is the header object and is described with them.⁶⁹¹⁰ Live key tests (P, B, L, 1-5) were not performed in this pass; interaction is documented from keyTyped() and the published control list, not from a timed generator session.⁶⁴

Edition 0 (token 164000000) carries Size=Small, Speed=Lively, Lights=5, Facade=Frontier, Sensors=Linear, Alignment=Lawful, Population=Cluster, Magnification=1.0. The PNG is a black field with a dense white figure-eight or lemniscate knot at center and long radial white traces that fade toward the corners. A faint arc of accumulated strokes runs along the lower right. Lights are not drawn; showLights defaults false. The still is the halted 1000-step drawing, not a live walk.⁶¹¹

Edition 1 (token 164000001) is the first mint after start_datetime: Size=Small, Speed=Steady, Lights=5, Facade=Atomic A, Sensors=Nonlinear, Alignment=Lawful, Population=Cluster, Magnification=0.66. The PNG is a white field. Teal and near-black line masses form three clustered knots joined by a looping corridor, with straight sprays leaving the frame. Magnification 0.66 is visible as more empty margin than edition 0. Atomic A here reads as the white-ground, cool-teal set rather than Frontier's black-and-white.⁶¹¹

Edition 10 (token 164000010) is Size=Base, Speed=Lively, Lights=5, Facade=Atomic C, Sensors=Nonlinear, Alignment=Lawful, Population=Swarm, Magnification=1.0. The PNG fills the square: a heavy black S-curve spine, teal envelopes, and a packed swarm of overlapping traces. Swarm versus Cluster is visible as occupancy, not as a caption. Edition 20 (token 164000020) returns to Small / Steady / Atomic A / Cluster with Lights=4. Header edition 684 (token 164000684) is Base, Lively, Lights=2, Facade=Silt, Sensors=Nonlinear, Alignment=Lawful, Population=Small is beautiful, Magnification=1.0. Its PNG is a mid-gray field with sparse black and white filaments and a loose horizontal braid. Two lights and the Silt facade produce the most open drawing in the sample.⁶¹¹

Canonical token URLs use the chain/contract/id pattern. Displayed edition numbers are invocations.

Significance and limitations

Phototaxis is a locked Playground edition that puts a 2001 drawing machine on Ethereum without pretending the port is a new organism. The artist said so before launch: the 2001 core survives; the 2021 work is a narrowed long-form parameter set running in p5.js.⁴⁵ Technically it is an honest finite simulation. It draws for 1000 frames, stops, and leaves keyboard hooks to restart, zoom, or reveal the hidden lights. The Dutch-auction schedule published on the project page (10 ETH start, 0.5 ETH rest, drop every five minutes) is part of the 2021 Art Blocks sale apparatus, not a property of the drawing.⁷

Limits of this account are specific. Live generator key tests were not performed in the submitted research. Invocation 0's minter role was not read from logs. Individual token prices inside the Dutch auction were not recovered from receipts. gray.reas.com/phototaxis/ is listed on the dossier but was not separately fetched as a distinct body beyond the MicroImage studio page.³⁵ Before publication, the coordinator refreshed the complete three-wallet AB5D linked-account set and checked the chosen token owner against it. The owner matched. The exact requests, returned identity and observation time are retained in the evidence record, separately from the earlier research snapshot. This is current indexed ownership evidence; it does not establish the acquisition date or historical custody of the work.²

Unresolved questions - What ETH price did each sampled token actually pay under the published Dutch schedule? - Who minted token 164000000 on 18 September 2021, and under what project role? - Do keys 1-5 change only view scale, or do they also rebuild machine state because they call bang()? - What additional text, if any, lives at gray.reas.com/phototaxis/ that is not on reas.com/microimage? - Was the Ropsten mention in the 2021 note a test mint, and does a test-chain token still exist?