除了低级原生插件接口之外，Unity 还支持低级渲染扩展，这些扩展可在发生特定事件时接收回调。这主要用于实现和控制插件中的低级渲染，并使低级渲染能够与 Unity 的多线程渲染一起使用。
Due to the low-level nature of this extension the plugin might need to be preloaded before the devices get created. Currently the convention is name-based namely the plugin name must be prefixed by “GfxPlugin”. Example: GfxPluginMyFancyNativePlugin.
The rendering extension definition exposed by Unity is to be found in IUnityRenderingExtensions.h and it’s provided with the editor.
These extensions are supported on all platforms supporting native plugins.
In order to take advantage of the rendering extension, a plugin should export UnityRenderingExtEvent and optionally UnityRenderingExtQuery. There is a lot of documentation provided inside the include file.
A plugin will get called via UnityRenderingExtEvent whenever one of the builtin events is triggered by Unity. The callbacks can also be added to CommandBuffers via CommandBuffer.IssuePluginEventAndData or CommandBuffer.IssuePluginCustomBlit command from scripts.