What can be a consequence of excessive overdraw in Unity?

Excessive overdraw refers to the phenomenon where multiple pixels are unnecessarily rendered multiple times during the rendering process. This typically occurs when transparent objects overlap or when layers in a scene are rendered without optimal efficiency. When overdraw is excessive, it becomes computationally expensive because the graphics processing unit (GPU) has to work harder to process these overlapping fragments even if they are not visible on the screen.

As a result, the consequence of excessive overdraw is slower game performance. This performance degradation can lead to lower frame rates, longer load times, and an overall less responsive gameplay experience. Properly managing overdraw is critical to maintaining smooth performance, particularly in complex scenes with many overlapping transparent or semi-transparent objects. Reducing overdraw can involve optimizing scene layout, minimizing the use of transparency, and employing techniques such as occlusion culling to improve rendering efficiency.