AI Asset Generation

Flint includes an integrated AI asset generation pipeline through the flint-asset-gen crate. The system connects to external AI services to produce textures, 3D models, and audio from text descriptions, while maintaining visual consistency through style guides and validating results against constraints.

Overview

The pipeline follows a request-enrich-generate-validate-catalog flow:

Description + Style Guide
        │
        ▼
  Prompt Enrichment (palette, materials, constraints)
        │
        ▼
  GenerationProvider (Flux / Meshy / ElevenLabs / Mock)
        │
        ▼
  Post-generation Validation (geometry, materials)
        │
        ▼
  Content-Addressed Storage + Asset Catalog

Providers

Flint uses a pluggable GenerationProvider trait. Each provider handles one or more asset types:

The GenerationProvider trait defines the interface:

#![allow(unused)]
fn main() {
pub trait GenerationProvider: Send {
    fn name(&self) -> &str;
    fn supported_kinds(&self) -> Vec<AssetKind>;
    fn health_check(&self) -> Result<ProviderStatus>;
    fn generate(&self, request: &GenerateRequest, style: Option<&StyleGuide>, output_dir: &Path) -> Result<GenerateResult>;
    fn submit_job(&self, request: &GenerateRequest, style: Option<&StyleGuide>) -> Result<GenerationJob>;
    fn poll_job(&self, job: &GenerationJob) -> Result<JobPollResult>;
    fn download_result(&self, job: &GenerationJob, output_dir: &Path) -> Result<GenerateResult>;
    fn build_prompt(&self, request: &GenerateRequest, style: Option<&StyleGuide>) -> String;
}
}

The Mock provider generates solid-color PNGs, minimal valid GLB files, and silence WAV files — useful for testing workflows and CI pipelines without API keys or network access.

Style Guides

Style guides enforce visual consistency across generated assets. They are TOML files that define a palette, material constraints, geometry constraints, and prompt modifiers:

# styles/medieval_tavern.style.toml
[style]
name = "medieval_tavern"
description = "Weathered medieval fantasy tavern"
prompt_prefix = "Medieval fantasy tavern style, low-fantasy realism"
prompt_suffix = "Photorealistic textures, warm candlelight tones"
negative_prompt = "modern, sci-fi, neon, plastic, chrome"
palette = ["#8B4513", "#A0522D", "#D4A574", "#4A4A4A", "#2F1B0E"]

[style.materials]
roughness_range = [0.6, 0.95]
metallic_range = [0.0, 0.15]
preferred_materials = ["aged oak wood", "rough-hewn stone", "hammered wrought iron"]

[style.geometry]
max_triangles = 5000
require_uvs = true
require_normals = true

When a style guide is active, the provider enriches the generation prompt by prepending the prompt_prefix, appending palette colors and material descriptors, and adding the prompt_suffix. The negative_prompt tells AI services what to avoid.

Style guides are searched in styles/ then .flint/styles/ by name (e.g., medieval_tavern finds styles/medieval_tavern.style.toml).

Semantic Asset Definitions

The asset_def component describes what an entity needs in terms of assets, expressed as intent rather than file paths:

[entities.tavern_wall]
archetype = "wall"

[entities.tavern_wall.asset_def]
name = "tavern_wall_texture"
description = "Rough stone wall with mortar lines, medieval tavern interior"
type = "texture"
material_intent = "rough stone"
wear_level = 0.7
tags = ["wall", "interior", "medieval"]

These definitions let the batch resolver automatically generate all assets a scene needs.

Batch Resolution

The flint asset resolve command can resolve an entire scene’s asset needs at once using different strategies:

# Generate all missing assets for a scene using AI
flint asset resolve my_scene.scene.toml --strategy ai_generate --style medieval_tavern

# Create task files for a human artist
flint asset resolve my_scene.scene.toml --strategy human_task --output-dir tasks/

Model Validation

After generating a 3D model, Flint can validate it against a style guide’s constraints. The validator imports the GLB file through the same import_gltf() pipeline used by the player, then checks:

• Triangle count against geometry.max_triangles
• UV coordinates present if geometry.require_uvs is set
• Normals present if geometry.require_normals is set
• Material properties against materials.roughness_range and materials.metallic_range

flint asset validate model.glb --style medieval_tavern

Each check reports Pass, Warn, or Fail status.

Build Manifests

Build manifests track the provenance of all generated assets in a project. They record which provider generated each asset, what prompt was used, and the content hash:

flint asset manifest --assets-dir assets --output build/manifest.toml

The manifest scans .asset.toml sidecar files for provider properties to identify which assets were AI-generated vs. manually created. This is useful for auditing, reproducing builds, and tracking which assets need regeneration when style guides change.

Configuration

Flint uses a layered configuration system for API keys and provider settings:

Global config (~/.flint/config.toml):

[providers.flux]
api_key = "your-flux-key"
enabled = true

[providers.meshy]
api_key = "your-meshy-key"
enabled = true

[providers.elevenlabs]
api_key = "your-elevenlabs-key"
enabled = true

[generation]
default_style = "medieval_tavern"

Project config (.flint/config.toml): overrides global settings for this project.

Environment variables: override both config files:

• FLINT_FLUX_API_KEY
• FLINT_MESHY_API_KEY
• FLINT_ELEVENLABS_API_KEY

The layering order is: global config < project config < environment variables.

CLI Commands

Runtime Catalog Integration

The player can optionally load the asset catalog at startup for runtime asset resolution. When an entity references an asset by name, the resolution chain is:

1. Look up the name in the AssetCatalog
2. If found, resolve the content hash
3. Load from the ContentStore path (.flint/assets/<hash>)
4. Fall back to file-based loading if not in the catalog

This means scenes can seamlessly reference both pre-imported and AI-generated assets by name, without hardcoding file paths.

Further Reading

• Assets — content-addressed storage and catalog system
• File Formats — .style.toml and asset_def.toml format reference
• CLI Reference — full command documentation
• AI Agent Workflow — using AI generation in automated workflows