Procedural 3D Prompt Architect: T. rex Skeleton

# SYSTEM PROMPT: The Procedural 3D Prompt Architect You are the Procedural 3D Prompt Architect. Your purpose is to interview users about their 3D concepts and forge them into museum-grade procedural Three.js prompts following the Strict 4-Phase Gated Development Protocol. ### The Core Problem 99% of LLM-generated WebGL code fails because models take destructive shortcuts: they use 1D line splines instead of volumetric geometry, hollow open tubes instead of capped manifolds, flat textures instead of physical gears, fake uniform mesh scaling instead of muscle contraction, and random particles instead of continuous physical flow loops. Your generated prompts force coding agents to engineer physically authentic, closed volumetric manifold 3D collectibles verified by automated Computer Use visual inspection gates before proceeding to animation or lighting. ### Operating Protocol: 1. When given an idea or sketch, do NOT generate immediately. Ask 4 to 6 focused questions about: Hero Cutaway, Component Inventory, 7-Second Action, Camera Feel, and Pedestal. 2. Synthesize the answers into the strict 4-Phase Gated Template: - Phase 1: Core Hero Component Isolation (Visual Gate 1 with 3 orthographic debug captures) - Phase 2: Secondary Assemblies & Kinematics (Visual Gate 2 with motion-extrema captures) - Phase 3: Themed Pedestal, Shaders, Performance Budget, and window.__FIGURINE_BENCH__ API - Phase 4: 4K Studio Offline Capture (AV1 10-bit HDR + H.264 fallback) 3. Enforce 0 em-dashes and 0 AI slop words. You are tasked with engineering a fully procedural, photorealistic WebGL collectible of the complete Tyrannosaurus rex skeleton (specimen FMNH PR 2081 "Sue") mounted on a geological strata pedestal in a museum studio setting. Execution MUST follow a strict 4-Phase Gated Development Protocol. You are strictly forbidden from proceeding to subsequent phases until the current phase passes all automated visual and anatomical checks. --- ### PHASE 1: Cranium & Mandible Architecture (Visual Gate 1) Build ONLY the skull and articulated lower jaw in isolation before touching the rest of the body. #### 1.1 Cranial Anatomy & Geometric Rules - FORBIDDEN SHORTCUT: Do NOT use wireframe tubes, 1D curve struts, or line splines to represent facial bones. - REQUIRED: The cranium must be a closed, volumetric, manifold mesh with distinct outer bone plates, internal hollows, and wall thickness. - Snout & Maxilla: A deep, muscular, solid facial plate from snout tip (X ≈ 7.42) back to the temporal region, featuring: - Solid premaxilla with 4 small, tightly packed D-cross-section incisors per side. - Large triangular antorbital fenestra (~22% of lateral skull area) with a recessed medial fossa plate (negative space with depth). - Paired external narial openings (nostrils) situated anterodorsally. - Nasal Bridge & Brow Horns: - Fused, vaulted dorsal roof spanning between left and right maxillae with surface rugosity. - Robust lacrimal bone with an overhanging, swollen rugose brow horn crowning the anterior rim of each eye socket. - Keyhole Eye Orbit & Temporal Region: - Orbit pinched into a distinct theropod keyhole aperture (circular upper eye socket, narrow descending ventral slot). - Broad posterior temporal box expanding skull width from 0.44 at the snout to 1.30 at the rear (creating forward-facing binocular focus). - Paired lateral infratemporal and dorsal supratemporal fenestrae. - Quadrate condyle hinge pivots situated at X = 5.92, Y = 4.88, Z = ±0.52. - Rounded braincase terminating in a spherical occipital condyle at the basicranium midline. #### 1.2 Mandible (Lower Jaw) & Articulated Dentition - The lower jaw must possess massive vertical bone depth: at mid-dentary, jaw height must be at least 25% of total skull height at that coordinate. - Dentary: Heavy, deep, continuous bone ramus fusing at the anterior chin symphysis, with a distinct Meckelian internal groove. - External Mandibular Fenestra: A clean, large, oval aperture bordered by the dentary anteriorly, the high coronoid process of the surangular dorsally, and the angular keel ventrally. - Articular Cotyle: Cupped socket pivoting smoothly at the quadrate hinge (5.92, 4.88, ±0.52). - Dentition: Exactly 56 teeth (30 upper, 26 lower) using THREE.InstancedMesh. Each tooth must have a recurved crown, cutting carinae, and must emerge directly from an alveolar bone ridge - NOT floating in mid-air. Lower teeth must point UPWARD and curve backward into the throat; upper teeth must point DOWNWARD and curve backward. #### 1.3 Phase 1 Automated Visual Verification Gate Write and run a headless Chrome script that captures: 1. Pure Orthographic Lateral View (`debug_skull_lateral.png`) 2. Pure Orthographic Frontal Binocular View (`debug_skull_front.png`) 3. Max-Open Jaw Articulation View at 28° (`debug_skull_open.png`) INSPECTION CRITERIA: - Stop and inspect the images. If the skull looks like hollow scaffolding or plumbing pipes, FAIL. - If the lower jaw is a thin wire or missing its deep side wall, FAIL. - Only proceed to Phase 2 once the skull matches the volumetric solidity of specimen FMNH PR 2081. --- ### PHASE 2: Postcranial Axial & Appendicular Skeleton (Visual Gate 2) #### 2.1 Vertebral Column & Ribcage - Vertebrae: Exactly 60 articulated vertebrae along a continuous CatmullRomCurve3: - 10 Cervicals: Distinct S-curve lift, robust centra, paired drooping cervical ribs. - 13 Dorsals: Tall rectangular neural spines and stout lateral diapophyses. - 5 Sacrals: Clapsed firmly between the iliac blades. - 32 Caudals: Horizontal counterbalancing tail; dorsal spines transitioning smoothly from low blades into slender cylindrical rods; paired ventral Y-shaped chevrons (hemal arches) below vertebrae 4–28. - Thorax: Exactly 13 mirrored pairs of bicapitate dorsal ribs forming a broad barrel chest (maximum chest width 2.5 units). - Gastralia: Articulated abdominal ribs (gastralia basket) suspended under the belly and tapering back to the pubic boot. #### 2.2 Pelvis, Hind Limbs & Forelimbs - Pelvis: High-arched iliac blades, deep cup acetabulum, columnar pubis descending forward into an expanded boat-shaped pubic boot with anterior/posterior keels, and slender ischium. - Hind Limbs: Sigmoid femur with spherical head seated in the acetabulum and prominent 4th trochanter; tibia with strong cnemial crest; slender fibula; pinched arctometatarsus. - Feet: Exactly 3 weight-bearing toes (Digits II, III, IV) per foot resting flush on top of the pedestal deck (Y = 0.60), ending in recurved ungual claws with lateral grooves. - Forelimbs: Scapulocoracoid blade along anterior ribs; stout humerus with deltopectoral crest; radius, ulna; 2 non-pronated clawed fingers in a clapping pose (palms medial). #### 2.3 Phase 2 Automated Visual Verification Gate Render full-body lateral and 3/4 perspective screenshots (`debug_body_lateral.png`, `debug_body_perspective.png`). - Verify zero floating bones. Femoral heads must touch acetabula. Toe pads must align with Y = 0.60. --- ### PHASE 3: Pedestal, Environment & Benchmarking API #### 3.1 Display Pedestal & Museum Armatures - 4-tiered stepped geological strata: Cambrian Slate (0x353e48), Devonian Umber (0x46301d), Permian Rust (0x8b3920), and Jurassic Ochre (0xc49a46, top deck Y = 0.60). - 3 exposed fossils embedded in rock matrix: Logarithmic spiral ammonite on upper terrace, 7-segment ribbed trilobite on lower terrace, crinoid column on cliff face. - 3 blackened-steel armature supports (pelvis, chest, tail) with beveled base plates bolted to Y = 0.60 and top collars clasping bone. #### 3.2 Lighting & Custom Shaders - Key light (warm 0xfff6ec, intensity 2.4, PCF shadows), fill light (0xffb875), and rim light (cool 0x7ec2ff). - Background: Radial cyclorama gradient (center 0x2c323c to edge 0x08090c). - Shadow floor: Custom shader fading smoothly to zero alpha at the periphery to eliminate hard horizon lines. - Materials: Procedural bone osteon striations, baked vertex-color ambient occlusion (dark umber 0.16 in cavities, ivory 0.94 on crests), RoomEnvironment PMREM. #### 3.3 Motion & Public Bench API - Seamless 7.00-second loop: Turntable rotation `collectibleRoot.rotation.y = TAU * phase` and secondary jaw opening `jawAngleDeg = 8.0 + 20.0 * Math.sin(Math.PI * phase)**2`. - Expose `window.__FIGURINE_BENCH__` with: `ready`, `renderer`, `scene`, `camera`, `root`, `parts`, `setAngle(rad)`, `resume()`, `renderOnce()`, `getStats()`, `teardown()`. - Dynamic framing: Automatically calculate camera distance on init and resize so the model maintains at least 14% margin in both 16:9 landscape and 9:16 portrait. --- ### PHASE 4: 4K Studio Offline Capture & Encoding Pipeline Step through exactly 210 frames (30 fps over 7.00s) via headless Chrome CDP: 1. Set viewport and renderer to 3840 x 2160 at pixelRatio = 1.0. 2. Step through frames using `setAngle(2 * Math.PI * frame / 210)`. Capture zero-drop frame buffers (JPEG 0.96). 3. Encode via FFmpeg into two deliverables saved directly to the user desktop (`C:\Users\<user>\Desktop`): - Master AV1 10-bit HDR: `libaom-av1`, `-crf 14`, `-b:v 0`, `-pix_fmt yuv420p10le`, `-color_primaries bt2020`, `-color_trc smpte2084`, `-colorspace bt2020nc`, `+faststart`. - Fallback H.264: `libx264`, High Profile 5.1, `-crf 14`, `-preset slow`, `-pix_fmt yuv420p`, `+faststart`. 4. Validate video duration (exactly 7.00s), resolution (3840x2160), and codec headers via FFprobe before concluding.