# Responsive objects

Kochu Studio · Research and prototype notes · 7 November 2026

The earlier catalogue included light-up objects, optical flip prints, folds and a zoetrope. This release explored a different question. Can the painting supply the path, alignment target, or reveal that makes an object worth handling? We developed 20 distinct mechanisms or material responses, then compared each across all five paintings.

The [twenty interactive studies](interactive-demos.html) cover every form in this release. They include optical reveals, linked mechanisms, responsive materials, and textiles you can rearrange by hand. The catalogue previews show intended physical states. Source examples establish that the underlying principles work in their own settings. The dimensions, finishes and performance of a Kochu Studio sample would need their own tests.

## Light and reflection

| Concept | What the source demonstrates | What a studio sample would test |
| --- | --- | --- |
| Mirror-Decode Print | A cylindrical mirror can reconstruct an image from a distorted drawing. The Met’s example uses a seventeenth-century engraving after Simon Vouet. [The Metropolitan Museum of Art](https://www.metmuseum.org/art/collection/search/393576) | Print the computed mat and calibrate a polished cylinder with a marked viewing position. Check glare, radius and viewing height. |
| Caustic Projection Tile | Papas and colleagues milled optical surface patches that redirected light into a target image. [Goal-Based Caustics](https://rgl.epfl.ch/publications/Papas2011Goal) | Solve a relief for one large motif with a fixed light and target plane. Check tolerances before attempting the complete painting. |
| Shadow-Fin Sculpture | Tim Noble and Sue Webster projected recognisable portraits from three-dimensional assemblies. [MoMA exhibition](https://www.moma.org/calendar/exhibitions/4798) | Cut a small array of fins and tune the light position. Check whether the key silhouette holds when the light or screen moves slightly. |
| Rain-Reveal Field Card | A water-responsive screen ink can become translucent when wet. Its manufacturer specifies paper, board and canvas, with a light underprint for a cleaner dry mask. [SFXC technical product description](https://www.sfxc.co.uk/products/hydrochromic-wet-and-reveal-screen-printing-ink-paper-and-board) | Make lightened underprint swatches and compare dry masking, wet contrast, repeat use and paper distortion. |
| Flash-Reveal Pocket Token | Glass beads or prisms can return light towards its source, producing contrast for an observer close to the light. [3M Scotchlite](https://www.3m.com/3M/en_US/scotchlite-reflective-material-us/industries-active-lifestyle/active-lifestyle/how-retroreflection-works/) | Cut a simplified motif in reflective film and compare ambient light, phone flash and off-axis views. Check adhesion to the token. |

### What the mirror demo verifies

The flat graphic was computed from a cropped original using a cylindrical reflection model. For every point on the visible mirror, the model follows the reflected viewing ray back to the flat print. The angle control repeats that lookup for a rotated viewer. The reveal comes from sampling the warped print itself.

Across the five digital maps, the nominal view reconstructed the central crop with a mean absolute error of 2.43–3.33 levels per RGB channel on a 0–255 scale. At 34 degrees off-axis, the same comparison gave 55.68–67.08 levels. The model uses parallel viewing rays and an ideal cylindrical surface. A finite viewing distance, surface quality and glare remain physical questions.

[Try the mirror reveal](mirror-proof.html)

### What the caustic demo verifies

The model assigns 12,544 ideal acrylic facets to points sampled from a tonal crop of Red Meridian. It computes an orientation for each facet, then traces the incoming and outgoing rays using Snell’s law. At the design position, all rays land on their assigned targets in the model. Moving the light or screen changes where they land. The displayed amber palette encodes intensity. The model omits Fresnel losses, manufacturing tolerances, and a continuous relief surface. [Goal-Based Caustics](https://rgl.epfl.ch/publications/Papas2011Goal) · [Specular transmission](https://www.pbr-book.org/4ed/Reflection_Models/Specular_Reflection_and_Transmission)

[Try the caustic projection tile](caustic-projection.html)

## Mechanical motion

| Concept | What the source demonstrates | What a studio sample would test |
| --- | --- | --- |
| Cam Lift Relief | Cams and followers convert a hand crank into repeatable movement. [Exploratorium automata guide](https://www.exploratorium.edu/sites/default/files/tinkering/files/Instructions/cardboard_automata_guide_final_screen.pdf) | Build a paperboard crank that registers three art-bearing pieces once per turn. Check binding, phase and guarding. |
| Geneva Index Dial | A four-slot Geneva drive advances by quarter turns with a locked dwell between steps. [Carnegie Mellon mechanism tutorial](https://www.cs.cmu.edu/~rapidproto/mechanisms/chpt8.html) | Turn through four painting details in a single window and measure registration at each stop. |
| Scissor Stretch Sculpture | Linked scissor members can extend and collapse together. [Extendable support structures patent](https://patents.google.com/patent/US6928683B1/en) | Separate rigid art tiles evenly. Check orientation, pivot clearance and stops. |
| Gravity Trace Maze | A rolling ball can be steered with a tilting playfield. [BRIO Labyrinth instructions](https://www.brio.us/spieleanleitungen/ecm/Spielanleitungen/7312350340006_PINFO_34000_Play_Leaflet_4000-851%20E.pdf) | Route a captive ball along a painted contour and check corner radii, tilt effort and enclosure. |
| Counterweight Horizon | Sliding a weight on a beam can bring it to equilibrium. [Science Museum Group steelyard](https://collection.sciencemuseumgroup.org.uk/objects/co57930/chinese-steelyard-balance-19th-century) | Register two pieces of the painting at balance. Check adjustment travel and repeatability. |

## Materials that respond

| Concept | What the source demonstrates | What a studio sample would test |
| --- | --- | --- |
| Palmprint Card Sleeve | Screen inks can lose colour when warmed past a specified temperature and recover when cooled. [Hallcrest technical data sheet](https://www.thermographics.com/Portals/0/Documents/Specialty%20Ink/Test%20Kit/PDS012%20Rev02.pdf) | Try a hand-warmed replaceable insert and compare contrast and recovery through a protective finish. |
| Humidity Curl Frame | Cross-grained wood bilayers bend as humidity varies. Published tests used larger changes than many indoor spaces see. [Rüggeberg and Burgert](https://pmc.ncbi.nlm.nih.gov/articles/PMC4383548/) · [Correa et al.](https://dspace.mit.edu/entities/publication/2620f163-12c2-470e-a840-d6f1ad7db479) | Compare unprinted and sparsely printed strips across realistic indoor humidity changes. Measure travel and time lag. |
| Snap Relief Pocket Tile | Flexible shell geometry can produce stable inverted states. [APS silicone shell tests](https://meetings-archive.aps.org/mar/2016/m1/248/) · [Liu et al.](https://arxiv.org/abs/2108.06499) | Test an unprinted dome first, then measure inversion force and coating wear. |
| Magnetic Contour Slate | A sealed display can draw dark lines when a magnetic pen brings particles to its front surface. [Pilot magnetophoretic display patent](https://patents.google.com/patent/US5151032A) | Adapt an intact insert with a printed tracing guide. Check stroke contrast, stylus retention and erasure. |
| Breeze Vane Register | Ned Kahn’s Wind Veil uses individually hinged plates moved by air. [Ned Kahn project notes](https://nedkahn.com/portfolio/wind-veil) | Measure the airflow needed to turn three desktop vanes and see whether they return to a registered image. |

## Objects reshaped by hand

| Concept | What the source demonstrates | What a studio sample would test |
| --- | --- | --- |
| Auxetic Cutwork Print | Connected, rotating units can open and change the proportions of a sheet. [Liu, Choi and Mahadevan](https://softmath.seas.harvard.edu/wp-content/uploads/2022/09/2022-11.pdf) · [MIT kinetiX](https://www-prod.media.mit.edu/publications/kinetix-designing-auxetic-inspired-deformable-material-structures/) | Compare a paper and a textile-backed cutout. Check how the gaps alter the image and how many cycles the hinges survive. |
| Reweavable Ribbon Frame | An over-under weave controls which faces of strips are exposed. [Hirshhorn weaving activity](https://hirshhorn.si.edu/explore/weave-it-together/) | Reweave printed bands in two orders and check strip tension and motif legibility. |
| Drawcord Smock Panel | Drawstrings and channels can gather textile into controlled folds. [Powerhouse collection](https://collection.powerhouse.com.au/object/23480) | Compare open and gathered layouts for readable colour rhythm and even cord tension. |
| Turn-Through Cloth Vessel | Two fabric faces can be assembled into a reversible container. [Reversible fabric basket pattern](https://www.spotlightstores.com/en-nz/projects/easter-projects/easter-reversible-fabric-baskets-project) | Evert a vessel from a full composition to a close crop. Check seam bulk and stability in both states. |
| Hand-Combed Pile Plaque | Brushing velvet changes pile direction and the way it reflects light. [James Dunlop Textiles](https://www.jamesdunloptextiles.com/journal/trends-inspiration/handling-care-velvets) | Try contrasting pile directions under one lamp, then check how well the mark resets when brushed back. |

## First proofs

1. **Mirror-Decode Print.** The browser result establishes the image geometry. A print and polished cylinder would test how easy the reveal is to find in a room.
2. **Cam Lift Relief.** Paperboard and a hand crank are enough to test whether the artwork’s registration creates a satisfying moment before building a finished object.
3. **Rain-Reveal Field Card.** A small screen-printed swatch can test the key uncertainty quickly. Compare the dry mask and wet contrast on one lightened crop.

Catalogue scores use the existing 40% artwork fit, 35% visual impact and 25% production feasibility rubric. A concept can score highly on impact while still requiring specialist fabrication. No production prices or physical performance figures were assigned.