Draw Call is a technical term that is extremely important in rendering and optimizing game graphics (technical art). An API command that the CPU issues to the graphics card (GPU) by specifying mesh and material parameters and telling it to ``draw this 3D model.''
An analogy in the real world: In contrast to the restaurant kitchen (GPU), the waiter (CPU) ``goes back and forth for each dish and passes the order individually''
Draw Call is, ``A single order command in which the waiter (CPU) in the hall shouts out to the chef (GPU) in the kitchen, ``Make this dish (mesh) with this seasoning (material)!'' and passes the order.'' If the waiter had to go back and forth to the kitchen 100 times to arrange 100 cherry tomatoes (objects) on the table, and each time he ordered one, he would say, ``Make me one cherry tomato!'' '' (100 draw calls), no matter how good the chef's skill (GPU performance) is, the waiter's legs (CPU) will get tired and the restaurant won't be able to run. I summarized the order on one piece of paper and said, ``Send me 100 cherry tomatoes at once!'' ” (batching) is required.
Illustration: Draw Call Infographic that clearly illustrates the basic processing flow and mechanism of (draw call) in Japanese.
Detailed mechanism and operating principle
Static batching (Static Batching), dynamic batching, SRP Batcher, or GPU Using Instancing, multiple draw calls are sent to the GPU at once, reducing the call load on the CPU side.