> [!abstract] Summary > **TOP + ROP Fetch — parallel rendering of multiple render layers / ROPs.** Build a TOP network that fetches each USD Render ROP (one per render layer) and renders them as parallel tasks. Combine with a Wedge node to also vary parameters per task. --- # TOP Fetch Render Layer - **Goal:** render **multiple ROPs simultaneously** by driving them from a TOP network. - Use **TOP Network** + **ROP Fetch** node. ![[file-20241110013230779.png]] ![[file-20241110013350945.png]] --- # Pattern 1. **TOP Network** inside the LOP graph (or in a parent context). 2. **ROP Fetch** TOP node — pointed at the USD Render ROP you want to render. 3. Repeat for each render layer (one ROP Fetch per ROP). 4. Optionally add a **Wedge** upstream to wedge parameters across all fetches (see [[../../TOPNET/6.121 HOUDINI TOP network|HOUDINI TOP Network]]). 5. **Schedule** — local for testing, **Deadline** for the farm. --- # When to Use - **Per-layer renders** — character / environment / FX layers rendered in parallel from a single scene. - **Variant renders** — render every variant of an asset in one go. - **Parameter sweeps** — Wedge + ROP Fetch to test multiple shader / sampling values. --- # 🔗 Related - [[../SOLARIS MOC|SOLARIS MOC]]. - [[../../TOPNET/6.121 HOUDINI TOP network|HOUDINI TOP Network]] — Wedge fundamentals. - [[../../TOPNET/Houdini Deadline|Houdini → Deadline]] — schedule the TOPs on the farm. - [[SOLARIS Cloning|SOLARIS Cloning]] — alternative for parallel renders without TOPs. - [[../../../../ARTFX OSMIUM/DEADLINE/DEADLINE MOC|OSMIUM DEADLINE MOC]] — farm context.