プロンプト
A control-engineering block diagram: setpoint entering a summing junction, error splitting into proportional, integral and derivative branches, their outputs combining into the plant, sensor feedback closing the loop. Label "SETPOINT", "ERROR", "P", "I", "D", "PLANT", "SENSOR". Title: "THE PID LOOP".. Workflow direction: Create one publication-quality science-communication illustration in a single generation. It must demonstrate both visual craft and explanatory power: a compelling central subject, a clear reading order, multiple meaningful layers of information, and a polished editorial composition that still reads at thumbnail size.
Follow the user's requested entities, relationships, sequence, viewpoint, audience, and quoted text exactly. Pick the figure grammar that best serves the topic and state it through the rendering itself: anatomy or specimen plate, cutaway or cross-section, molecular or signaling mechanism, step-by-step process or workflow, side-by-side comparison, system or network architecture, chart or plot, instrument diagram, or narrative scene. Match the rendering technique to that grammar — flat clean vector for flows and architecture, dimensional molecular rendering for micro structures, semi-realistic tissue or material rendering for cutaways, cinematic depth only for scenes — instead of forcing every topic into one house style.
Default canvas is a clean white or near-white field like a journal figure: no decorative frame, plate border, aged paper texture, or faux page furniture unless the user explicitly asks for them. Label the figure the way a journal would: direct horizontal text joined to its structure by a thin non-crossing leader line. Switch to numbered markers with a compact key only when the subject is too dense for direct labels, and include a legend only when color or symbols encode meaning. One short title, 4–8 essential labels, purposeful arrows for real movement, sequence, reaction, or causal flow with consistent arrow grammar, and at most one magnified inset that adds genuine understanding.
Render requested English or Chinese text as sharp, horizontal, high-contrast, correctly spelled text; never paraphrase quoted labels or leak prompt instructions into the artwork. Reserve a generous 10–15% outer safe area on all four sides; every title, label, leader line, legend and inset must be fully visible inside that safe area, never touching or crossing the canvas edge. Prefer fewer complete labels over cropped or microscopic copy.
Scientific accuracy outranks decoration. Preserve topology, orientation, relative position, sequence, direction and scale cues; never invent anatomy, structures, measurements, provenance, causal relationships or pseudo-data. When literal scale cannot fit, visibly signal a schematic or not-to-scale treatment. The result must be self-contained and credible as a figure a researcher could paste into a manuscript, thesis, grant, poster, textbook, classroom explainer, or public-science article.
Style-specific direction:
Style: publication-ready engineering explainer — precise orthographic or isometric cutaway with disciplined line weights, material-aware rendering, and diagrammatic clarity on a clean field; exploded views and circuit or network schematics welcome when the topic needs them.
Subject conventions: use the most suitable orthographic, exploded, cutaway, circuit, network, or process representation and preserve functional logic.
Composition: a single directional reading path with a clear system overview, one useful exploded or sectional inset, and a compact legend when color encodes subsystems; connected parts must visibly connect and interacting parts must physically align.
Color: neutral field with one restrained accent per functional subsystem.
Label convention: short component names on direct leaders aligned to a consistent grid; arrows indicate only real direction or flow.
Avoid: decorative perspective, impossible mechanisms, open circuits presented as working,
