Async Asset Pipeline

For a modern 3D engine, blocking the main thread to load hundred-megabyte model assets is unacceptable. Myth builds a robust asynchronous Asset Server that keeps the render loop perfectly smooth.

1. Acquiring & Managing Assets

The engine's resources are managed uniformly by engine.assets, which owns the lifetime of textures, models, materials, and meshes.

Loading Basic Resources

Loading most local or networked resources is very straightforward:

// Load a texture asynchronously
let albedo = engine.assets.load_texture("assets/uv_grid.png", ColorSpace::Srgb, true);

// Load an HDR environment map asynchronously
let env = engine.assets.load_texture("assets/studio.hdr.jpg", ColorSpace::Srgb, false);
scene.environment.set_env_map(Some(env));

glTF Scene Prefabs

For complex glTF or GLB files, the engine parses the node tree, binds skins, and automatically installs animation mixers:

let model_prefab = engine.assets.load_gltf("assets/model.glb");
// Instantiate once the prefab is ready (see timing below)
let root_node = scene.instantiate(prefab.as_ref());

2. Critical Rules for Async Timing

Myth's loading pipeline is fully asynchronous. This means that when you call scene.instantiate(), the scene node tree is created immediately, but the underlying GPU resources (vertex buffers, texture data) may still be queued for background upload.

⚠️ Important Pitfall: Beware of "First Few Frames" Timing

Because model loading is asynchronous, it is normal for a model to not be fully loaded into the scene during the first few frames after startup.

If your low-level logic strictly depends on geometry data existing immediately, you must explicitly handle this async timing.

This timing mismatch often doesn't panic outright; instead it manifests as extremely subtle rendering bugs (sudden flickering, shadow tearing). Best practice: in your on_update loop, always confirm resource readiness via Option or asset state checks before running logic that depends on the asset being fully loaded.

3. Practical Guide

For the full workflow of loading glTF, instantiating, playing animations, and handling readiness checks, see the guide chapter Assets, glTF & Animation.