LWRP

Lightweight Render Pipeline (LWRP) is a Unity Scriptable Render Pipeline designed to deliver high performance on mobile and lower-end hardware while supporting modern shading. It was created as an efficient alternative to the built-in render pipeline and to more heavyweight options, prioritizing a smaller runtime footprint and simpler shader variants.

Architecturally, LWRP is implemented as a package that replaces the default render pipeline with a lightweight renderer asset. It uses a ScriptableRenderer and configurable render passes, enabling developers to tailor the rendering path to their target platforms. The pipeline integrates with Unity’s Shader Graph for authoring materials and allows the addition of custom render features through the Scriptable Render Pipeline framework.

Features of LWRP focus on performance and broad platform support. It provides forward rendering with a streamlined lighting model, reduced shader complexity, and optimized culling and batching. The pipeline supports Shader Graph materials, basic real-time and baked lighting, and configurable shadows. Post-processing and other visual effects could be integrated via packages, with the emphasis on maintaining a low overhead.

Limitations accompany its performance goals. LWRP offers a smaller feature set compared with the Built-in Render Pipeline or the High Definition Render Pipeline, and some advanced effects such as complex lighting workflows, certain reflection and global illumination options, and some high-fidelity rendering features were limited or unavailable.

Lifecycle and legacy: LWRP was later evolved into what is now known as the Universal Render Pipeline (URP). Unity transitioned to URP to unify cross-platform performance with a broader set of features. Projects using LWRP can migrate to URP using official upgrade tools and guidelines, after which they can access updated performance optimizations and broader functionality.