Metal asset streaming workflow

Metal Asset Streaming Workflow

Scope

Own the GPU-facing asset path: package or source asset, CPU staging, upload, residency, eviction, and use in a frame. Do not hide all asset ownership in a generic cache; name the asset manager and the renderer boundary that consumes it.

Read streaming-model.md before introducing a heap, residency set, sparse resource, or fast-resource-loading path.

Workflow

1. Measure the actual symptom: first-use hitch, sustained stutter, missing detail, out-of-memory termination, or GPU resource-pressure growth.
2. Inventory asset classes, size ranges, mip/LOD behavior, residency lifetime, upload path, and current CPU/GPU ownership.
3. Choose the simplest durable path:
   • ordinary texture or buffer loading for bounded content;
   • explicit heaps or residency sets when allocation and lifetime grouping are the problem;
   • fast resource loading when packaged asset loading is proven to dominate;
   • sparse resources only when content size or streaming granularity justifies their mapping complexity.
4. Define budget and eviction policy before loading more data: per-class budget, minimum viable mip/LOD, prefetch trigger, eviction trigger, fallback content, and telemetry.
5. Synchronize upload, mapping, and use. A resource must not become visible to a render pass until its data and mapping work have completed.
6. Validate memory and frame pacing on target hardware with representative content and movement, not a synthetic empty scene.

Guardrails

• Do not equate unified memory with unlimited GPU memory or omit budgeting on Apple silicon.
• Do not call a resource zero-copy without demonstrating compatible storage, format, synchronization, and absence of conversion/readback.
• Keep sparse residency and asset LOD decisions data-driven; do not infer success from allocated bytes alone.

Handoffs

• metal-game-rendering-workflow for command encoding, renderer lifetime, and resource consumers.
• xcode-game-profiling-workflow for memory pressure, VM behavior, GPU timeline, or hitch evidence.
• game-porting-toolkit-workflow for a source port that needs GPTK’s asset and resource translation guidance.

Output

Return the measured symptom, selected loading/residency path, budget and fallback policy, synchronization boundary, validation evidence, and unproven hardware assumptions.