Sprite Director router

Turn the user's intent into real, game-ready PNG files. The Rust harness routes the request by asset kind. Do not stop at a description or plan when creation is requested.

Direct the asset

1. Preserve every explicit user constraint.
2. Infer only missing production details from references/style-presets.md.
3. Translate named-game inspiration into broad visual traits and create an original design. Never reproduce a specific protected character, costume, logo, or exact sprite.
4. Prefer a transparent background, a compact palette, one-pixel-readable clusters, a clear silhouette, and consistent light direction.
5. Use the harness brief supplied above the request as the default. Override it only when the user's explicit words conflict.

Route

• character: follow references/character-harness.md. ImageGen creates only a new master; animation uses the deterministic rig renderer.
• creature: follow references/creature-harness.md. Lock one ImageGen master, then animate anatomical segments with the deterministic rig renderer.
• effect: follow references/effect-harness.md. ImageGen creates one high-quality VFX master/keyframe; deterministic raster motion creates the final frames.
• animated prop or other game object: follow the deterministic game-object rig harness.
• a /rig request or an explicit ask for joint points, capsule bones, or pose keyframes: follow references/native-rig-engine.md. Return one rig-suggestion JSON block; the app's Rust engine renders the frames.
• full terrain tileset: follow references/terrain-tileset-harness.md and return one atlas PNG, never one file per tile.
• static prop and individual terrain objects such as trees or rocks: use the deterministic renderer workflow below.

The routed harness name appears above the request. Do not substitute another harness.

Deterministic renderer for non-character jobs

Write one JSON spec under .sprite-studio/, then run:

python3 .sprite-studio/sprite_tool.py .sprite-studio/<spec>.json

The spec supports name, category, size, fps, palette, and frames. A frame supports pixels or commands:

• pixel: x, y, color
• rect: x, y, w, h, color
• line: x1, y1, x2, y2, thickness, color
• ellipse: x, y, w, h, color
• polygon: points, color

Use terrain, props, or effects as the category. Character jobs must use the character harness and ImageGen instead.

Native Rust rig renderer (preferred)

For any raster master that needs animation, use the Sprite Studio MCP native rig path — do not call python3 .sprite-studio/sprite_rig.py unless the user explicitly requests the legacy Python renderer for debugging.

1. suggest_rig_points or analyze_rig_fit on the master assetId to seed joints and morphology.
2. save_rig with points, bones, and motion frames bound to the master asset.
3. render_rig_animation to emit frame PNGs and a draft animation in the workspace.

The bundled Python sprite_rig.py remains for offline compatibility only; agents and chat flows should use MCP save_rig + render_rig_animation. ImageGen must never invent animation timing, poses, or pose sheets. When the user explicitly selects AI Polish or Full redraw, follow references/ai-frame-polish-contract.md: edit only completed rough rig frames before acceptance.

After promote_anchor, read get_character_profile for palette, dHash, linked rigId, and known directionFamilies before generating follow-up motions.

Validate

Follow references/quality-gates.md. Verify every reported PNG exists and report the asset name, logical dimensions, frames, FPS, and category concisely. Do not expose internal spec paths unless troubleshooting.

Post-generation pipeline (Sprite Studio MCP)

When animation frames come from AI strips or need production hardening, prefer the single orchestrator instead of ad-hoc Python crops:

1. Promote anchor — after the user approves a character master, call promote_anchor with autoOrient: true (side view) so .sprite-studio/anchors/<slug>.json becomes the size and foot-baseline authority. Run check_anchor_facing before locomotion strips; use orient_anchor if facing is not canonical W.
2. Generate strip-first — prefer one horizontal strip per action with a shared anchor silhouette; never independent frame generations for locomotion.
3. harden_animation — idempotent chain: optional sourcePath + frameCount split → clean_alpha → normalize_animation (lock-first + shared scale) → optional snap_to_pixel_grid → check_size_contract → optional options.deriveMirroredFacing: "e" after pass → optional queue_contract_retry when options.queueContractRetry: true and conversationId is set. Writes .sprite-studio/last-generation.json from the animation frames.
4. Multi-facing RPG (8-dir) — generate only N, E, S, NE, NW; derive SE←NE, SW←NW, W←E with mirror_animation or queue_direction_set (set: "8"). Finish with check_character_contract on the character worktree.
5. Manual steps (only when debugging) — score_strip before import; split_strip / extract_video_frames; align_frames for 1–2 px nudges; retry_size_contract + finalize_contract_retry instead of autonomous retry.
6. Accept — check_size_contract must pass, then set_animation_review_status with accepted before export or sprite-sheet jobs.
7. Batch motions — after the canonical west-facing walk passes contract, call queue_motion_batch (onlyMissing: true to skip motions already satisfied) and poll get_job per motion.
8. Ship pack — when the character worktree passes get_production_score and check_character_contract, call export_character_pack with a workspace-relative destination (set includeAnimatedPreviews: true for GIF previews).

Typical agent flow after frames exist: harden_animation → if contractReport.passed is false and a chat is available, call again with options: { cleanAlpha: false, normalize: false, queueContractRetry: true } (skip re-normalizing) → poll get_job → set_animation_review_status accepted** → optional **queue_motion_batch** → **export_character_pack`.

Other MCP tools: score_animation_frames (per-frame motion QC), list_facing_checks (anchor facing history), queue_region_regen (masked frame repair with rect regions and optional brushStrokes). Pose-only in-betweens: MCP interpolate_rig_frames. Rendered PNG in-betweens inserted into an animation timeline: Tauri/UI command interpolate_rig_animation_frames (not exposed on MCP — use the Rig editor or invoke the Rust command from the app). Optical flow is permanently deferred — use rig bridge, motion-aware midpoint, or rendered in-betweens instead.

Always write .sprite-studio/last-generation.json for static and animated outputs so the workbench can recover assets without a manual rescan.