Render Pass (Render Pass / ScriptableRenderPass)

Render Pass (render pass / ScriptableRenderPass) is a technical term that is extremely important in rendering and optimizing game graphics (technical art). An explanation of the smallest unit of rendering that encapsulates a series of drawing processes (e.g. drawing only depth, drawing only opacity, executing post processing, etc.) in Unity's render pipeline (URP, etc.).

Real-world analogy: On an automobile assembly line, a ``dedicated booth for painting the body (Render Pass)'' is temporarily added to modularize the process of applying a special glitter coating before sending it to the next booth

Render Pass is a module that subdivides the entire process of creating a 3D picture (render pipeline) into several small independent ``individual work booths (passes)''. First, there is a ``booth for assembling the car frame (depth pass),'' then a ``booth for painting the car (opaque pass),'' a ``booth for installing window glass (translucent pass),'' and finally a booth for waxing (post-processing pass). Since each pass is fully encapsulated, developers can create their own ``new special booth for adding mud stains to the car body (custom render pass)'' and insert it between lines to achieve the ultimate unique graphics expression without risk.

Detailed mechanism and operating principle

Create a class that inherits `ScriptableRenderPass` in C#, specify the drawing destination buffer with `ConfigureTarget`, program the specific drawing process for the command buffer in the `Execute` method, and insert it into the pipeline via the Renderer Feature.