How do you optimize game performance with AI and NPC behavior?

1 Use a behavior tree

A behavior tree is a graphical representation of the logic and decision-making process of an AI or NPC agent. It consists of nodes that define the actions, conditions, and transitions of the agent. By using a behavior tree, you can simplify and modularize your AI code, making it easier to debug, maintain, and extend. You can also use a behavior tree to optimize your game performance by implementing features such as dynamic prioritization, parallel execution, and conditional aborts.

2 Implement level of detail

Level of detail (LOD) is a technique that reduces the complexity and detail of an object or a scene based on its distance from the camera or the player. By using LOD, you can save resources and improve your game performance by rendering only what is necessary and relevant for the player's experience. You can apply LOD to your AI and NPC behavior by adjusting the frequency, accuracy, and range of their actions, animations, and sensors according to their proximity and visibility to the player.

3 Use finite state machines

A finite state machine (FSM) is a model that defines the states and transitions of a system or an agent. It is a simple and efficient way to implement AI and NPC behavior, as it allows you to easily control the flow and logic of your code. You can use finite state machines to optimize your game performance by minimizing the number of states and transitions, avoiding unnecessary calculations and checks, and using triggers and events to change states.

4 Apply object pooling

Object pooling is a design pattern that reuses and recycles objects that are frequently created and destroyed, such as bullets, particles, and enemies. By using object pooling, you can reduce the overhead and latency of memory allocation and garbage collection, which can affect your game performance. You can apply object pooling to your AI and NPC behavior by creating a pool of pre-instantiated agents that can be activated and deactivated as needed, instead of creating and destroying them on the fly.

5 Use coroutines

Coroutines are functions that can be paused and resumed at any point, allowing you to perform asynchronous and concurrent tasks without blocking the main thread. By using coroutines, you can optimize your game performance by spreading out the workload of your AI and NPC behavior over multiple frames, avoiding long and expensive calculations that can cause frame drops. You can use coroutines to implement features such as pathfinding, steering, and sensing.

6 Test and profile

The last and most important tip to optimize your game performance with AI and NPC behavior is to test and profile your game regularly. Testing and profiling are essential steps to identify and fix any performance issues, bottlenecks, or bugs in your game. You can use various tools and methods to test and profile your game, such as debug logs, frame rate counters, performance monitors, and profilers. By testing and profiling your game, you can measure and improve the impact of your AI and NPC behavior on your game performance.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?