Unity配置（Fixed Timestep=0.002、DefaultContactOffset=0.0001）下台球游戏性能优化求助

Hey Joel, let's tackle this performance slowdown while keeping that tight, responsive collision feel you've built. Your current settings (DefaultContactOffset=0.0001 and Fixed Timestep=0.002) are pushing the physics engine hard—here's how to balance speed and precision:

1. Tweak Your Physics Timing & Contact Offset (The Low-Hanging Fruit) #

• Adjust DefaultContactOffset: A value of 0.0001 is extremely small, forcing the engine to detect tiny, unnecessary collision overlaps on every physics update. Try bumping it up incrementally (start with 0.0005 or 0.001) and test collision responsiveness. For fast-moving pool balls, a slightly larger offset won't ruin the feel but will cut down on redundant collision checks.
• Re-evaluate Fixed Timestep: 0.002 means your physics engine is running 500 updates per second—way higher than most games (most use 50-60 updates/sec). Gradually increase this value (try 0.004 for 250 updates/sec or 0.005 for 200) and test if collision accuracy holds. If you still need high precision for fast shots, keep it higher but pair it with other optimizations below.

2. Optimize Collision Detection Overhead #

• Simplify Colliders: Stick to primitive colliders—use Sphere Collider for pool balls and Box/Plane Collider for the table. Ditch any Mesh Colliders unless absolutely necessary; they're way more computationally expensive.
• Layer-Based Collision Filtering: Set up collision layers so pool balls only interact with other balls, the table, and pockets. Disable collisions between balls and non-game objects (like UI, decorations) to eliminate unnecessary checks.
• Disable Physics for Static/Idle Balls: When a ball's speed drops below a small threshold (e.g., 0.1 m/s), set it to Kinematic or disable its Rigidbody component. Re-enable it only when another ball hits it—this stops the engine from wasting cycles on stationary objects.

3. Fine-Tune Physics Engine Solver Settings #

• Limit Continuous Collision Detection (CCD): CCD is great for preventing fast-moving balls from passing through each other, but enabling it on every ball adds overhead. Only enable CCD on balls that are actively moving at high speeds (you can toggle this via code when a ball is struck).
• Reduce Solver Iterations: Lower the Solver Iterations and Solver Velocity Iterations values (default often 6 and 10). Try 4 and 8 first—pool ball collisions are simple rigid-body interactions, so you likely don't need the highest precision here. Test to make sure balls still bounce and roll naturally.

4. Profile to Target Exact Bottlenecks #

Use your engine's built-in profiler (e.g., Unity Profiler, Unreal Stats) to dig into where the physics overhead is coming from:

• Is collision detection taking up most of the time? Focus on adjusting contact offset, collider complexity, or layer filtering.
• Is the physics solver the culprit? Tweak timestep or solver iterations.

This way you can make targeted changes instead of guessing!

内容的提问来源于stack exchange，提问作者Joel Oliveira