In current versions of Unity, there are three types of Render Pipeline which are: Built-in RP, Universal RP (called Lightweight in previous versions), and High-Definition RP.
It is worth asking, what is a Render Pipeline? To answer this, the first thing to understand is the pipeline concept.
A pipeline is a series of stages that perform a bigger task operation. So, what does Render Pipeline refer to? This concept could be thought of as the complete process that a polygon object must take to be rendered onto our computer screen; it is like an object traveling through Super Mario pipes until it reaches its final destination.
So, each Render Pipeline has its own characteristics, and depending on the type you are using, will affect the appearance and optimization of objects on the screen in terms of: material properties, light sources, textures, and all the functions that are occurring internally within the shader.
Now, how does this process happen? For this, you must learn about its basic architecture. Unity divides this architecture into four stages which are:
- Application stage.
- Geometry processing phase.
- Rasterization stage.
- Pixel processing stage.
Please note that this corresponds to the basic model of a Render Pipeline for real-time rendering engines. Each of the mentioned stages has threads that will now be defined.