What causes a fast Unity melee swing that tunnels past enemies?

At high swing speed the hitbox moves more than its own width between physics frames, so it never overlaps the target on any single step and the trigger is never evaluated at the contact point.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Fast Melee Swings Missing the Enemy in Unity

Quick answer: Sweep the hitbox between its previous and current position each frame with Physics.OverlapCapsule or a CapsuleCast instead of relying on a single-frame overlap.

If a fast slash visibly passes through an enemy but deals no damage, the hitbox teleported past them between physics steps. Sweeping the volume across the frame catches the contact. Here is how.

How to fix it

1. Sweep instead of overlap

Each frame, build a capsule from last frame's hitbox position to this frame's and call Physics.OverlapCapsule or CapsuleCastAll. This tests the whole path, not just the endpoint.

2. Cache the previous transform

Store the hitbox transform every FixedUpdate so you have a valid start point for the sweep. Reset it when the swing begins to avoid a stale segment.

3. Raise the fixed timestep if needed

For extreme speeds, lowering Fixed Timestep in Time settings gives more physics samples per swing, but prefer sweeping since it is cheaper than a global step change.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

The errors you never hear about are the ones quietly costing you players. Visibility turns them into a worklist.