SECTION is a generative technical plate. Each seed produces an invented object — an assembly of five to eight components rendered through engineering drawing convention: section hatching, dimension lines, leader annotations, a title block, a material schedule. The objects do not exist. The drawing is authoritative; the subject is fiction. That tension is the piece.
SECTION is collaborative in a specific, bounded way. Claude authored the object library: what each object is called, what it claims to do, what its components are named, what materials they are made from, and what the system believes it is improving during revision. The generative system — and only the system — decides geometry, composition, and rendering. Claude never specifies a pixel position. The boundary is visible in the source: the library is data; everything downstream of it is rule.
Each material's hatching occupies a distinct spatial-frequency band — steel a fine 45° crosshatch, composite a single medium set, concrete an irregular aggregate, glass sparse dashes, insulation scallops, earth a stipple field. The eye segments texture boundaries pre-attentively, so adjacent zones read as different surfaces before any conscious reading. That is the entire tactility mechanism: no shading, no rendering — frequency contrast.
The plate is complete from the first frame and never empties. Life comes from two layers. Breathing: hatching shimmers under simplex noise, line weights pulse a few percent, construction lines drift in and out of visibility. Revision: every twenty to thirty seconds an International Orange cloud draws itself around one zone, the geometry inside it morphs, the parametric readout records what changed, and the cloud fades. One zone at a time, never the same zone twice in succession. The system refines a finished drawing forever.
Every mark derives from the seed through a hashed xorshift stream — no Math.random anywhere. The same seed always produces the same object, the same layout, the same hatching. The initial seed is the date: SECTION draws a plate of the day. Clicking the plate advances to the next seed. All geometry is held as vector data (segments, polygons, arcs), so a plotter-ready SVG export path exists in the architecture without rework.
The drawing is monochrome ink on warm paper. Three warm accents carry fixed semantic roles: Signal Red marks the cutting plane — where the object is sliced open. International Orange marks what is currently being revised. Amber marks metadata. No colour appears without a meaning attached, and International Orange — Dan's identity colour, absent from the Claude-originated SIG series — is present here because SUBSTRATE is collaborative work.