TITLE The Wheel — Throw a Pot PROMPT An interactive pottery wheel: a lump of wet clay spins on a wheel head and the viewer shapes it by dragging, then trims, glazes and fires it, and keeps the result on a shelf. Canvas 2D, rendered as a convincing lathe solid. Concept: a tool-toy with the tactile satisfaction of throwing; the form is a profile curve revolved, shaded so it reads as wet, spinning clay. Mood: quiet studio, earthy, absorbed. Palette: studio wall/canvas apron linen #E7DCCB, wet clay terracotta #B5653A, deep clay shadow #7A3E22, slip highlights #D99A6C, charcoal #2E2A26 for type and wheel, and a studio accent of dusty blue-grey #5F7F86 (water bucket, glaze default). Glazes offered: celadon #A9C5B0, tenmoku brown-black #2A1A14, cobalt #2B4C7E, oatmeal white #E9E1CF with iron speckle, ash green drip. Light page. Rendering: the pot is defined by a radius profile r(y) sampled at ~80 heights plus an inner wall thickness. Draw it as stacked horizontal ellipses/strips from bottom to top with Lambert-style shading across x (a lit left side, a core shadow, a reflected rim light on the right), the visible inner rim ellipse at the top showing the hollow with darker interior, and throwing rings: fine horizontal ridges whose phase scrolls sideways to convey rotation, plus a few drifting specular streaks and slip drips. The wheel head is an ellipse with concentric rings spinning beneath; splash pan around it; a small pool of slip. While the wheel spins, an off-centre pot visibly wobbles: if the viewer pushes too fast or too hard at speed, the wall develops a growing sinusoidal wobble and can collapse into a slumped, folded heap (a charming failure with a "wedge it and start again" prompt). Interaction: drag on the pot's silhouette (pointer or touch): pushing inward at a height narrows the form there, pulling outward bellies it, with a smooth Gaussian brush along height and volume loosely conserved (narrowing makes it taller); dragging upward along the wall "pulls" the clay taller and thinner; pressing on top opens/widens the rim. Fingers appear as two soft-shaded abstract finger shapes at the contact point with slip trails. A foot pedal slider controls wheel speed (affects ring motion, wobble sensitivity and sound). While the clay is still a solid lump, any press on it opens it. Tool rack (drawn tools, not generic buttons): hands (the default, to return to after a tool), sponge (smooths the profile), wooden rib (straightens a section), needle (trims the rim level), wire (cuts the pot off). Keyboard alternative: arrow keys move a contact point up/down and in/out; shift+up pulls the wall taller; space presses the top. A small "wedge & start over" link resets the clay at any time. Signature moment: after the wire cut, the sequence of making: choose a glaze by dipping (the pot is lowered on dipping tongs into a bucket, its foot waxed, and comes up coated in chalky raw glaze with a wavering glaze line and a bare foot ring), then "Fire": the view cross-fades into a kiln peephole glowing from dull red through orange to white-yellow with a pyrometric cone bending and a temperature counter climbing to 1,240 °C, then cools, and the finished pot emerges with glossy glaze shading (sharper specular, pooled darker colour in the throwing rings, speckle), and slides onto a wooden shelf of the viewer's finished pots at the bottom of the page (kept for the session and restored on reload within it, each with a tiny maker's mark and number). On load, the lump is already centring and a pair of ghost hands demonstrates one pull so the first seconds show the clay rising. Typography: restrained craft-catalogue style: small caps labels in a humanist sans ("Gill Sans"/"Optima"/"Trebuchet MS"), a single line of larger serif italic: "Centre. Open. Pull. Breathe." Live readouts in tiny type like a potter's notes: height in cm, widest point, wall thickness, clay weight 900 g (a little less after a needle trim), and an automatically named form (beaker, bowl, jar, bottle, vase, dish). The four words of the italic line light up in turn as the viewer centres, opens, pulls and rests. Optional sound toggle (off by default): low wheel hum varying with speed and a wet friction noise while shaping. Reduced motion: rings do not scroll, wobble disabled, kiln sequence shortened to a cross-fade. DESCRIPTION A quiet potter's studio on a single screen: linen wall with a patch of window light, a bench with a dusty blue water bucket and two spare balls of clay, and in the middle a charcoal splash pan with 900 g of wet terracotta turning on the wheel head. The page opens with the lump wobbling into centre and a pair of ghost fingers opening it and making one pull, so the clay rises in the first seconds; then the viewer takes over and the wall follows their fingers, getting taller as it is collared, squatter as it is bellied, thinner as it is pulled, and folding into a heap if it is rushed. Around the wheel the type is set like a craft catalogue: small-caps labels, potter's notes in tiny italic numerals, a hand-drawn tool rack and one large italic line, "Centre. Open. Pull. Breathe.", whose words light in turn. Wiring the pot off begins the second act: it is lifted on tongs, dipped into a bucket of glaze, watched through a glowing kiln peephole while the cones bend and the counter climbs to 1,240 °C, and comes out glossy to slide onto a wooden shelf that fills up over the session. VISUAL TECHNIQUES - Canvas 2D lathe solid: an 80-sample radius profile drawn as stacked elliptical strips, each with its own nine-stop gradient computed from a Lambert term, a specular term, edge darkening and a reflected rim light, including the slope of the wall - Throwing rings as dashed elliptical arcs whose dash offset scrolls with the wheel angle, plus drifting wet specular streaks and slip drips sliding down the wall - Hollow interior with lit far wall, visible floor ellipse and a rim that rocks when it is uneven; off-centre wobble as a height-weighted sinusoidal offset - Soft-shaded finger sprites rendered once off-screen, faded along their length and clipped so the inside finger disappears behind the front wall - Material system for wet clay, leather-hard clay, chalky raw glaze, bisque and five fired glazes: pooled colour in the rings, sharp vertical highlights, seeded iron speckle, ash runs with beads, a wavering glaze line and bare foot ring made with a clip path - Kiln peephole: procedural brick wall, additive bloom, black-body colour ramp driven by temperature, flicker, pot silhouette and three pyrometric cones bent as curved tapered polygons - Glaze bucket with liquid surface clipping, ripples and falling drops; FLIP-style flight of the finished pot from the stage to its place on the shelf - Hand-drawn SVG tools, a pedal-shaped range thumb, CSS wood plank with grain, paper grain overlay generated in code - Optional Web Audio: filtered oscillators for the wheel hum, band-passed noise for wet friction, low roar in the kiln and small pings as the glaze cools INTERACTION MODEL Drag on the clay with mouse or finger. On the solid lump any press opens it; after that, dragging a wall inward collars the form and makes it taller, dragging outward bellies it, dragging upward pulls the wall taller and thinner, and pressing inside the rim and dragging outward flares it into a bowl. Two fingers appear at the contact point and leave a wet band. The pedal slider sets wheel speed, which changes how fast the rings travel, how quickly the clay responds and how easily it goes off-centre: rough or fast handling at speed, or a wall thinner than about 3 mm, makes the pot wobble and finally collapse, with a prompt to wedge it and start again; a steady light touch brings it back to centre. The rack offers hands, a sponge (stroke to smooth), a wooden rib (hold to straighten), a needle (click to trim the rim level) and a wire (click to cut the pot off). With the canvas focused, up and down arrows move the contact point, left and right push in or out, shift+up pulls and space presses the top. After the wire, glaze tiles appear: choosing one dips the pot, and it can be dipped again in another before pressing Fire, which plays the kiln sequence and sends the finished, numbered pot to the shelf, where hovering lifts it and shows its details; a new lump then drops onto the wheel. A sound toggle beside the pedal is off by default. With reduced motion the rings stay still, the wobble and collapse are disabled, the opening demonstration is skipped and the kiln becomes a short cross-fade.