> [!abstract] Summary > **Payload LOP** — like Reference, but with **deferred loading**. Payloads are not loaded into memory until explicitly requested, dramatically improving scene-loading time for heavy assets. Use for environments, set dressing, hero assets you're not currently editing — anything that's "in the scene" but doesn't need to be live. --- # Payload - **Purpose:** Similar to a **Reference**, but designed for **deferred loading** of USD data. - **Use:** Reference large assets or scene parts that can be **loaded on demand** to optimise memory and performance. - **Behaviour:** Payloads are **not loaded into memory until explicitly requested** — opening the scene file is fast. - **Typical Use Case:** Heavy assets or background elements not always needed during lookdev / layout work. --- # Payload vs Reference | | **Reference** | **Payload** | |---|---|---| | Loaded immediately on stage open? | ✅ Yes | ❌ No (deferred) | | Composes data into the stage? | ✅ Yes | ✅ Yes (once loaded) | | Can be loaded / unloaded interactively? | ❌ No | ✅ Yes | | Best for | Always-needed data | Heavy / optional data | --- # Loading & Unloading In the Scene Graph Tree, **right-click a prim** → **Load Payload** / **Unload Payload**. You can also batch-set via: - **Load LOP** — load specific payloads. - **Configure Stage LOP** — set the **Initial Load Set** (`LoadAll` / `LoadNone` / `LoadAndUnloadDescendants`). --- # Typical Workflow - **Environment dressing** — set every scattered asset as a payload; load only the ones near the camera. - **Character library** — payload all characters, load only the ones in the current shot. - **Heavy FX caches** — payload sims, load only when rendering or reviewing. --- # 🔗 Related - [[../SOLARIS MOC|SOLARIS MOC]]. - [[SOLARIS Reference VS Sublayer VS Merge|Reference VS Sublayer VS Merge]] — non-deferred alternatives. - [[SOLARIS Component builder - Explore Variants|Component Builder]] — component output uses a Payload by default. - [[../../../../PROTOCOL/USD/Notes/USD KNOWLEDGE/6.30 USD Theory|USD Theory — Payload]]. - [[../TROUBLESHOOTING/SOLARIS General Optimisation|General Optimisation]] — perf guidance.