Why does Physics.OverlapSphere return colliders at their old positions?

Unity's physics engine maintains its own internal representation of collider positions. When you move a Transform directly (without a Rigidbody or with isKinematic), the physics world does not update until the next FixedUpdate or until Physics.SyncTransforms is called. Overlap queries use the physics world state, not the Transform state, so they see the previous positions.

What does Physics.autoSyncTransforms do?

When Physics.autoSyncTransforms is true (the legacy default), Unity automatically synchronizes all Transform changes to the physics world before every physics query. This is convenient but expensive — it triggers a full sync even for a single overlap check. Since Unity 2018.3, this defaults to false for performance, meaning you must call Physics.SyncTransforms() manually when needed.

Should I call Physics.SyncTransforms every frame?

No. Calling it every frame defeats the purpose of disabling autoSyncTransforms. Instead, call it only when you need accurate query results after moving transforms outside of physics simulation — for example, after teleporting an object and immediately running an overlap check. For most gameplay code, performing overlap queries in FixedUpdate after physics runs naturally avoids the issue.

Fix: Unity Physics.Overlap Returning Stale Results

Quick answer: Physics.OverlapSphere and Physics.OverlapBox query the physics world, not Transform positions directly. If you move objects via Transform.position and immediately query, the physics world still has the old positions. Call Physics.SyncTransforms() after moving objects, or perform your queries in FixedUpdate where the physics state is already current.

Here is how to fix Unity Physics.Overlap returning stale results. You teleport an enemy to a new position, then immediately run Physics.OverlapSphere to check what is nearby — and it returns colliders that were near the enemy’s old position, not the new one. Or you move a trigger zone and the overlap query thinks nothing is inside it yet. The physics world is out of sync with your transforms.

The Symptom

Physics.OverlapSphere, Physics.OverlapBox, Physics.OverlapCapsule, and their non-allocating variants (OverlapSphereNonAlloc, etc.) return colliders based on positions from the previous physics step. Objects you just moved appear to be in their old locations. Raycasts exhibit the same problem — they hit colliders at their previous positions.

This is most noticeable when you move objects in Update and then immediately query. In FixedUpdate the problem is less apparent because physics has just simulated.

What Causes This

The physics world is separate from Transform state. PhysX (Unity’s physics engine) maintains its own copy of collider positions and orientations. When you set transform.position, only the Transform component updates immediately. The physics world updates during the next FixedUpdate simulation step or when explicitly synced.

Physics.autoSyncTransforms is false. Since Unity 2018.3, autoSyncTransforms defaults to false in new projects for performance. The old behavior (automatically syncing before every query) was expensive because it forced a full broadphase rebuild on every overlap check. With it disabled, you gain performance but must manage sync timing yourself.

Querying in Update after moving in Update. If you move a collider in Update frame N and query in the same Update frame N, the physics world still has frame N-1 positions (or whatever the last FixedUpdate left).

The Fix

Step 1: Call Physics.SyncTransforms() when needed. After moving objects outside of physics simulation and before querying, sync the physics world explicitly.

// Teleport then immediately query
enemy.transform.position = newPosition;

// Sync physics world to match new Transform positions
Physics.SyncTransforms();

// Now overlap queries see the updated position
Collider[] nearby = Physics.OverlapSphere(newPosition, 5f);
Debug.Log("Nearby count: " + nearby.Length);

Step 2: Prefer querying in FixedUpdate. If your game logic allows it, perform overlap queries in FixedUpdate rather than Update. The physics simulation runs at the start of FixedUpdate, so collider positions are current by the time your code executes.

void FixedUpdate()
{
    // Physics just simulated — collider positions are current
    int count = Physics.OverlapSphereNonAlloc(
        transform.position, detectionRadius, results, enemyMask);

    for (int i = 0; i < count; i++)
    {
        ProcessTarget(results[i]);
    }
}

Step 3: Use Rigidbody.MovePosition for physics-driven movement. If you move objects with Rigidbody.MovePosition instead of setting transform.position directly, the physics engine integrates the movement during simulation and collider positions stay consistent with queries in the same FixedUpdate.

// Kinematic Rigidbody movement — physics stays in sync
private Rigidbody rb;

void FixedUpdate()
{
    rb.MovePosition(targetPosition);
    // Overlap queries after this in the same FixedUpdate see the new position
}

Step 4: Do not enable autoSyncTransforms globally. While setting Physics.autoSyncTransforms = true in Project Settings > Physics fixes the problem, it re-introduces the performance cost for every query in your entire project. Use targeted SyncTransforms() calls instead.

Performance Considerations

Physics.SyncTransforms() iterates over every transform that has moved since the last sync and updates the physics broadphase. If you have thousands of moving objects, calling it multiple times per frame is expensive. Batch your queries: move everything, sync once, then run all your overlap checks.

// Batch pattern: move all, sync once, query all
foreach (var unit in units)
    unit.transform.position = unit.targetPos;

Physics.SyncTransforms(); // One sync for all moves

foreach (var unit in units)
    unit.RunOverlapQuery();

“The physics world is a parallel universe. It only learns about Transform changes when you tell it to sync — or when FixedUpdate runs.”

2D Physics Too

The same issue applies to Physics2D.OverlapCircle and related 2D queries. Use Physics2D.SyncTransforms() for 2D physics. The setting is separate: Physics2D.autoSyncTransforms in Project Settings > Physics 2D.

SyncTransforms is not expensive for a few objects. It is expensive when you have thousands. Move, sync once, then query — do not sync between every move.