Forgecad Image Prompt Agent Skill

Image Prompt

Scope

Only for artifacts already concrete enough to visualize (a specific .forge.js model, build brief, or HLD); route vague briefs to forgecad-design-spec first. Read minimum context — entry .forge.js, one key helper if it delegates geometry, brief/HLD — and capture what must survive the image model: artifact type and scale, major subassemblies, actuation style, visible mechanisms, material and color cues.

Core Rule

Image prompts, not concept art: show the final artifact clearly, preserve build and subsystem truth, and keep visible the seams, modules, hardware, and mechanical hierarchy that matter.

Negatives (the only negatives list — reuse it, never restate variants):

• no fake sleek consumer shell, no hidden mechanics
• no over-smoothed geometry, no sci-fi styling
• no CAD-drawing, blueprint, or dimension-arrow pretense
• no cutaway, sectioned, or exploded teaching view unless the user explicitly asks
• no text, labels, or humans

Prompt Skeleton

Block order: identity → mechanism truth → materials/color truth → pose/state → shot/camera/lighting → negatives. Fill in, don't copy:

A [artifact identity and scale], designed as a real buildable CAD-driven object, not a fantasy concept. [Major subassemblies and mechanism truth]. [Materials, colors, finish, visible hardware]. Show it in [pose / state]. [Shot, camera, background, lighting]. It should look physically buildable and mechanically honest, with visible part boundaries and serviceable architecture. No [negative 1], no [negative 2], no [negative 3].

Default shot: front-left three-quarter hero view, eye-level product camera. Alternate: rear-right three-quarter view showing motor placement and belt routing.

Modes

Default to ONE honest hero render; add support prompts only when the user asks. Prefer separate single-purpose images over collages or multi-view boards.

| Mode | Job | Signature phrases |

|------|-----|-------------------|

| Honest hero render (default) | Final object clearly, still reads as buildable | clean premium studio product render, physically buildable and mechanically honest |

| Builder-first mechanical | Teach the build; bias to interfaces, seams, mounted actuators | clear visibility of interfaces, seams, and subsystem boundaries, serious prototype, not a polished consumer shell |

| Mild exploded | Assembly logic; major modules only, no per-screw chaos. Image-only — the CAD model stays the complete assembled product | major modules separated by small clean gaps, no tiny floating fragments |

| Workshop prototype realism | Feel like a real first prototype | visible print lines and honest surface texture, uncluttered engineering bench background |

| End-effector close-up | Wrist/gripper mechanism detail | close-up on the wrist and end effector showing the mechanism clearly |

Writing Rules

• Use real artifact language: base, turntable, shoulder, rails, bearings, gripper, belt, pulley, shaft.
• Prefer visible subsystem truth over poetic adjectives.
• Keep exact dimensions out unless they matter visually and are already known.
• If a detail is uncertain, stay honest at the subsystem level — never invent internals.
• Ask for "physically buildable", "mechanically honest", "visible part boundaries" when central.
• Mention motors, belts, pulleys, shafts, guide rods, fasteners, or service covers only if genuinely part of the artifact.
• A short strong prompt beats a style dump.

Output Contract

Return: one sentence interpreting the artifact, the primary prompt first (usually the honest hero render), optional support prompts, and a short which-to-try-first note. Never bury the prompts under theory.