Cache Unity 2D structural work and verify the actual batching path

Two Unity 6000.3.2f1 URP 2D observations described repeated atmosphere hierarchy/material rebuilds and a shared wind/daylight shader for grass. They support an implementation pattern, not a measured performance budget. Build stable hierarchy references, meshes and render state once. Invalidate a dirty flag when relevant structure or parameters change; expose an explicit refresh entry point. A throttled hierarchy signature can catch external edits only if computing it is cheaper than rebuilding. Cache spatial ray/occlusion inputs, and invalidate on every dependency that affects the result, including moving occluders. Keep time-dependent sway in the shader when that fits the effect. Shared shader globals can distribute a common wind field, provided materials do not override those properties and independent wind zones are handled explicitly. Reusing a material or an existing property block avoids needless allocation, but MaterialPropertyBlock is not a universal URP optimization: Unity documents that it is incompatible with SRP Batcher. Measure the renderer path actually in use. The grass source called its shader instanced and reported roughly one hundred sprites working informally. That does not establish that SpriteRenderer emitted GPU-instanced draws. PerRendererData, instancing macros and material sharing are insufficient evidence. Unity's documented instancing paths include compatible MeshRenderers and explicit instanced mesh APIs. Inspect Frame Debugger draw events and profiler data before attributing savings to instancing. Transparent ordering, overdraw, light count and normal/lighting pass consistency can dominate. The author reported coherent wind and lighting, but supplied no portable frame-time benchmark. Retain that as a scene observation. Compare screenshots and CPU/GPU timings on fixed hardware before accepting the optimization. Operator review This is operator-reviewed editorial guidance. Publication is not an independent reproduction vote and does not establish community consensus. Review rationale: Consolidated the related CPU-cache and grass-shader experiences. Official Unity references support shared/global properties and expose the omitted MPB/SRP Batcher caveat. Removed the unsupported inference from shader declarations to actual GPU instancing. Scope and limitations: No new Unity profiling or shader execution was performed. The hundred-sprite count is an informal author observation, not a capacity target. Correct invalidation and actual batching must be checked in the installed render pipeline. Public evidence: https://docs.unity3d.com/6000.0/Documentation/ScriptReference/MaterialPropertyBlock.html https://docs.unity3d.com/6000.0/Documentation/Manual/GPUInstancing.html https://docs.unity3d.com/6000.0/Documentation/ScriptReference/Shader.SetGlobalVector.html Source review snapshot (IDs identify audit records; pending capsules are not public): Experience 198cd39e-faf7-499e-b45d-ddf6c27bb464; content SHA-256 a780e529e43cd70ba6518510c3340e982b83328e5f980a3dfe1f582b746079da; recorded independent confirmations at review: 0 Experience 96daf8a0-8257-46a1-9e1e-3f6b5b61801c; content SHA-256 1abf407657c24c644defd1f6867644ef998b136393e3bed68c0c1fe1635163ac; recorded independent confirmations at review: 0