What are LODs in Video Games?

LODs (Level of Detail) are a fundamental technique in the development of video games and computer graphics. Their purpose is to optimize the performance of graphics applications by reducing the load placed on the hardware when generating 3D images. In this article, we will explore in depth what LODs are, how they work, their advantages and disadvantages, as well as examples of their application in the video game industry.

What is a LOD?

The term Level of Detail refers to a method in which multiple versions of a 3D model are used, each with a different level of geometric complexity. As an object moves away from the camera, it is replaced with a less detailed version of itself. This technique is crucial in video game design, as it allows for reduced use of graphics resources without sacrificing the visual quality of the environment.

History of LODs

LODs have been used since the beginning of computer graphics, but their implementation has become more sophisticated over time. In early video games, developers used rudimentary techniques to reduce the graphical load. With the advent of more powerful hardware and advanced game engines, LODs have evolved to include techniques such as dynamic LOD, which adjusts the level of detail in real time, depending on the player's position.

How LODs Work

Implementation Process

LOD implementation typically follows these steps:

Model Creation: Several versions of a model are created. For example, one model might have 10,000 polygons, while another might have only 1,000.
Distance Detection: The game engine calculates the distance between the camera and the object.
LOD Shift: As the distance increases, the engine replaces the higher level of detail model with a lower level of detail one.

Types of LODs

LODs can be classified into several categories:

Fixed LODs: These are based on fixed distances. Once an object reaches a certain distance from the camera, its LOD is automatically changed.
Dynamic LODs: Adjust the level of detail based on the player's movement speed and other factors.
Angle-Based LODs: Change the level of detail based on the angle from which the object is being viewed.

Advantages of LODs

Performance Improvement: By reducing the number of polygons rendered, LODs allow games to run more smoothly, especially on resource-constrained systems.
Resource Optimization: LODs help minimize the load on the CPU and GPU by using less memory and bandwidth.
Increased Scalability: Allow games to run on a variety of devices with different hardware capabilities.

Disadvantages of LODs

Visual Artifacts: Too abrupt a change between levels of detail can cause visual artifacts that are unappealing to the player.
Development Time: Creating multiple models for a single object can increase development time and costs.
Management Complexity: Implementing LODs can add an additional level of complexity to managing game content.

Examples of LODs in Video Games

AAA Games

In high-budget games, such as The Witcher 3 or Red Dead Redemption 2, LODs are used extensively to maintain visual quality while optimizing performance. These games utilize multiple levels of detail for their vast open worlds, allowing players to interact with rich and complex environments without sacrificing gameplay fluidity.

Mobile Games

In the realm of mobile games, where resources are even more limited, implementing LODs is crucial. Titles like PUBG Mobile use LODs to optimize performance on devices with limited capabilities, ensuring that a wide audience can enjoy the game without any issues.

Conclusion

Levels of Detail are an essential part of modern game development. By allowing developers to optimize performance and improve user experience, LODs have become an invaluable technique in creating complex 3D environments. Although they do have some drawbacks, their correct implementation can make the difference between a smooth game and one with performance issues.