Why does Unity Rigidbody teleport produce a visible smear?

With Interpolation enabled, the renderer interpolates between previous and current physics positions. After a teleport, the previous position is far away; the interpolation visibly smears between the old spot and the new for one frame. Call Rigidbody.position to teleport (not MovePosition) and immediately Physics.SyncTransforms or use Rigidbody2D.MovePosition with interpolation reset.

How do I teleport a Rigidbody without smear?

Set rb.position = newPosition and rb.rotation = newRotation, then call rb.ResetInertiaTensor() if needed. To prevent interpolation from smearing, you can briefly set Interpolation to None, perform the teleport, then restore. In Unity 2022+, use Rigidbody.position with Physics.SyncTransforms for cleaner sync.

Why does Rigidbody.MovePosition not work for teleporting?

MovePosition is a request that the physics system interpolates over the next physics step. It is designed for kinematic motion, not instant teleport. Use Rigidbody.position for instantaneous moves; reserve MovePosition for smooth kinematic following.

Fix: Unity Rigidbody Interpolation Jitter After Teleport

Quick answer: With Rigidbody Interpolation on, a teleport creates a one-frame smear from the old position to the new. Set rb.position directly (not MovePosition), then briefly disable interpolation (rb.interpolation = None) for the teleport frame, or use Physics.SyncTransforms() after the assignment.

Here is how to fix Unity Rigidbody teleports that produce a visible smear or stretched-out blur as the body lurches across the screen. You set rb.position to the destination, but for one frame the renderer draws a streak between origin and destination because Interpolation tries to smooth between the two physics frames. The fix is to disable interpolation just for the teleport.

The Symptom

An object teleports across the level. For one rendered frame, you see it smeared along the path. With interpolation off, the teleport is instant but ongoing motion looks choppy. With interpolation on, motion is smooth but teleports leave artifacts.

What Causes This

Interpolation tracks two positions. Rigidbody Interpolation/Extrapolation interpolates the rendered transform between the previous and current physics positions. After a teleport, the previous position is the old spot; the renderer slides smoothly between them.

MovePosition queues motion. If you used MovePosition instead of position, the request is interpolated over the next physics step, exacerbating the smear.

SyncTransforms missing. The visual transform may not catch up to the physics position until the next physics step without a manual sync.

The Fix

Step 1: Set position directly and reset interpolation.

using UnityEngine;

[RequireComponent(typeof(Rigidbody))]
public class Teleporter : MonoBehaviour
{
    private Rigidbody rb;
    void Awake() { rb = GetComponent<Rigidbody>(); }

    public void TeleportTo(Vector3 pos, Quaternion rot)
    {
        var oldInterp = rb.interpolation;
        rb.interpolation = RigidbodyInterpolation.None;

        rb.position = pos;
        rb.rotation = rot;
        rb.linearVelocity = Vector3.zero;
        rb.angularVelocity = Vector3.zero;
        Physics.SyncTransforms();

        rb.interpolation = oldInterp;
    }
}

The brief None during the teleport prevents Unity from smearing the visual.

Step 2: Use position, not MovePosition, for instant teleports.

// BAD: smooth-following request
rb.MovePosition(target);   // interpolated over next step

// GOOD: instant placement
rb.position = target;
Physics.SyncTransforms();

Step 3: Reset velocity to avoid carry-over. If the body had momentum before teleport, that momentum continues in the new position. For most teleports, zero velocity is what you want.

Step 4: For 2D, do the equivalent.

rb2d.position = newPos;
rb2d.linearVelocity = Vector2.zero;
Physics2D.SyncTransforms();

Step 5: For player teleports during a frame, sync the camera too. If a Cinemachine camera follows the player, it may also exhibit smear. Call vcam.OnTargetObjectWarped(player.transform, newPos - oldPos) after the teleport so the camera knows it is a discontinuity, not motion.

When To Keep Interpolation

Outside of teleports, leave Interpolation on for smooth visuals. Disable only for the teleport frame and restore. Always-off Interpolation produces jittery normal motion.

Understanding the issue

This bug class falls into a pattern that's worth understanding beyond the specific case. In Unity Engine, the underlying behavior is shaped by how the engine layers its abstractions - the public API you call, the runtime systems that respond, and the platform-specific implementations underneath. A bug at any layer can produce symptoms that look like they originate at a different layer. Triaging effectively means recognizing which layer the symptom belongs to, even when the gameplay code is what's visible.

The specific bug described above is the kind that surfaces during integration rather than unit testing. It depends on a combination of factors: the asset configuration, the runtime state, the platform's specific behavior. In isolation, each piece looks correct; in combination, the bug emerges. This is why thorough integration testing - playing the actual game in realistic conditions - catches things that automated tests miss.

Why this happens

This bug class disproportionately affects late-stage development. The work to surface it is interactive testing in realistic conditions, which only really happens after the gameplay is in place and assets are populated. Catching it early requires deliberate testing of conditions that look unimportant.

At the engine level, the behavior comes from a deliberate design decision in Unity. The engine team chose a particular trade-off - usually performance versus convenience, or generality versus specificity - and that trade-off has consequences when you push against it. Understanding the trade-off is what turns 'this bug is mysterious' into 'this bug is the expected consequence of this design'.

Verifying the fix

After applying the fix, the verification step has three parts: confirm the original repro is resolved, confirm no obvious regressions in adjacent functionality, and (for shipping titles) deploy to a small player cohort first and watch the crash and report rates. Each step catches something the others miss.

Reproducibility is the prerequisite for verification. If you can't reliably reproduce the bug pre-fix, you can't reliably verify it post-fix. Spend time getting a clean reproduction before you write any fix code. The fix is fast once you understand the reproduction; the reproduction is the slow part.

Variations to watch for

Related bug classes often share the same root cause. If you find yourself fixing this issue, look for cousins: similar symptoms in adjacent systems, the same data flow but a different value, or the same fix pattern in another module. The catalog of 'we've seen this before' becomes valuable institutional knowledge.

Adjacent bugs often share a root cause. After fixing the case you've found, spend an hour searching the codebase for similar patterns. What's the same call with different arguments? The same data flow with a different entity type? The same lifecycle issue in a sibling system? Each match is a candidate for the same fix, or a related fix that prevents future bugs of the same class.

In production

In shipping builds, this issue may interact with other production-only behavior. Stripping, encryption, asset bundling, and platform-specific code paths can each modify the symptoms. When players report a related issue, capture build SHA, platform, and any feature flags - those three fields cover most of the production-only variations.

When triaging a similar issue in production, prioritize gathering data over hypothesizing causes. A player report describes a symptom; what you need is a build SHA, a session timestamp, and ideally a screen recording or session replay. With those, the bug becomes tractable. Without them, you're guessing at hypothetical reproductions that may not match what the player actually hit.

Performance considerations

Performance implications matter when this bug class scales with player count or asset count. A bug that fires once per session is annoying; a bug that fires once per frame compounds. After fixing, profile the affected code path under realistic load. The fix that's correct for one entity may be too slow for ten thousand.

Diagnostic approach

Diagnosing this class of bug benefits from a structured approach: confirm the symptom, isolate the variables, hypothesize the cause, and verify the hypothesis before writing fix code. Skipping the isolation step is the most common mistake; without it, fixes often address symptoms while the underlying cause continues to produce other variations.

For Unity-specific diagnostics, the editor's profiler is the canonical starting point. Capture a representative frame with the symptom present; compare against a frame without the symptom; the diff often points directly at the cause. If the symptom is non-deterministic, capture multiple frames and look for the pattern - the cause is usually a state transition or a specific input value rather than a continuous effect.

Tooling and ecosystem

The tooling around this bug class matters as much as the fix itself. Good logging, accessible profilers, and clear error messages turn 30-minute investigations into 5-minute ones. If your project doesn't have visibility into this code path, the first fix should add the visibility - the second fix uses it.

Within Unity, the relevant diagnostic surfaces include the standard frame debugger, memory profiler, and engine-specific debug overlays. Each one shows a different facet of what's happening. The frame debugger reveals draw call ordering and state transitions; the memory profiler shows allocation patterns; the debug overlay reveals per-system state. Bugs that resist one tool usually surrender to another - the trick is knowing which tool to reach for first.

Edge cases and pitfalls

Platform-specific edge cases are worth enumerating explicitly. iOS handles backgrounding differently than Android; Windows handles focus changes differently than macOS. A fix that works on the development platform may not work on every target. Test on each shipping platform deliberately.

When writing a regression test for this fix, focus on the boundary conditions that surfaced the original bug. Tests that exercise the happy path catch obvious regressions; tests that exercise the boundary catch the subtler regressions that look like new bugs but are really the original returning. The latter are the tests that earn their keep over the long life of the project.

Team communication

Document the fix and its rationale in the commit message or attached engineering doc. Future engineers will encounter related issues; the rationale tells them whether your fix is reusable or specific to the case at hand. Without rationale, the fix gets reverted or copied incorrectly.

If this fix touches a system several engineers work in, a short writeup in the team's engineering channel helps. Not a full design doc - a paragraph explaining what was wrong, what's fixed, and what to watch for. Future engineers encountering similar symptoms will search for the fix; making it findable is a small investment that pays back later.

“Position teleports; MovePosition smooths. Disable interpolation for the teleport frame. Sync transforms. Restore.”

Related Issues

For physics jitter in general, see Physics Jittery Movement. For tunneling, see Physics Tunneling.

interpolation = None for one frame. position assignment. SyncTransforms. Restore. Clean teleport.