What does the Pin behavior actually do?

Pin captures the relative position and (optionally) angle between two sprites at the moment Pin To is called. Each subsequent tick, it updates the pinned sprite’s position to maintain that offset relative to the parent. The Mode setting controls whether angle follows.

Why does my pinned sprite drift when the parent rotates?

If Pin Mode is ‘Position only’, the offset is captured as world-space dx/dy. Rotating the parent doesn’t rotate the offset; the pinned sprite stays at the original world offset. Use ‘Position & angle (with offset)’ or ‘Rope style’ so the offset rotates with the parent.

How do I re-pin after a teleport?

Call Pin Unpin first, set the pinned sprite’s position to its new location, then call Pin To with the parent. The first Pin call captured the original offset; re-pinning captures the new offset.

Fix: Construct 3 Pin Behavior Offset After Rotate

Quick answer: Set Pin Mode to Position & angle (with offset). The default “Position only” mode captures world-space offsets that don’t rotate with the parent.

You pin a sword sprite to the player’s hand. The player rotates to face left. The sword stays oriented to the right and floats next to the player’s old facing direction. The pin maintains the offset but ignores rotation.

Pin Behavior Modes

The Pin behavior’s Pin To action takes a Mode parameter:

Position only — pinned sprite follows world-space dx/dy. Rotation of the parent has no effect on the pinned sprite’s position or angle.
Angle only — pinned sprite matches the parent’s angle but stays at its own position.
Position & angle — pinned sprite follows position and angle, but offset is captured in world space.
Position & angle (with offset) — pinned sprite follows position and angle, and the offset rotates with the parent.
Rope style — pinned sprite is “attached” via the closest point at pin time; useful for trailing tails.

For a sword or other accessory attached to a body part, you want Position & angle (with offset).

The Fix

// Event sheet, on weapon spawn
Sword.Pin.PinTo(Player, "Position & angle (with offset)")

The sword’s offset and angle are captured relative to the player’s rotation frame. When the player rotates, the offset and the sword’s angle both follow.

Why “Position only” Is Still Useful

Position only is the right choice for HUD elements pinned to a moving object — the HUD should follow its target but never rotate. A health bar above an enemy uses Position only so it always faces up regardless of how the enemy is rotated.

The rule of thumb: if the pinned sprite should look like part of the parent’s body, use offset rotation. If it should be a screen-aligned overlay, use Position only.

Re-Pinning After Teleport

If the pinned sprite or its parent teleports to a new location, the captured offset is now wrong. The pin will still attempt to maintain the old offset, which results in the pinned sprite snapping back to where it “should” be.

Unpin and re-pin:

// On teleport
Sword.Pin.Unpin()
Sword.SetPosition(Player.X + 12, Player.Y)
Sword.Pin.PinTo(Player, "Position & angle (with offset)")

The new pin captures the new offset cleanly.

Multiple Pinned Children

You can pin many sprites to the same parent. Each child captures its own offset independently. A character with sword, shield, and hat can have all three pinned with appropriate offsets, each following rotation correctly.

When the parent destroys, pinned children become unpinned automatically — but they don’t destroy. If you want them to die with the parent, listen for “On destroyed” on the parent and destroy each child.

Verifying

Rotate the parent 90 degrees at runtime. The pinned sprite should orbit around the parent and rotate by 90 degrees as well. If it stays in its original world position but the parent rotates around it, you’re using Position only. If it rotates around the parent but maintains its world-space angle, you’re using Position & angle without offset.

Understanding the issue

This bug class falls into a pattern that's worth understanding beyond the specific case. In Construct 3, 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 Construct 3. 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

For shipping games, the safest verification is a staged rollout. Apply the fix to 1% of players for 24 hours; watch the affected metric; expand if green. Skipping the staged rollout means the verification is the entire player base, which is too high a stakes for most fixes.

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

There's almost always a less obvious case where the same problem applies. The reported case is the one a player hit; the related cases hide because they're rarer or affect fewer players. After fixing the reported case, search the codebase for the pattern - one fix often unlocks several.

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

Live games surface this bug class at scale. What's a rare edge case in development becomes a daily occurrence once you have a few thousand concurrent players. The class isn't 'this player has a unique setup'; it's 'one in N thousand sessions will trigger this exact combination'.

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

If this issue manifests under high load (many actors, many particles, many network connections), profile the post-fix code path with realistic counts. The original cost was a bug; the new cost is real work, and real work has a budget.

Diagnostic approach

Before applying any fix, gather enough context to be confident you're addressing the actual cause and not a similar-looking symptom. The cheapest diagnostic step is reproducing the bug deterministically - if you can't get the same failure twice in a row, your fix attempts will be hard to evaluate. Lock down the reproduction first.

For Construct 3-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 Construct 3, 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

Edge cases for this class of issue often involve specific timing: the first frame after a state change, the last frame before a transition, frames where multiple subsystems update simultaneously. Reproducing these reliably is part of what makes the bug class hard to test.

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.

“Pin mode matters. Position only for HUDs, ‘with offset’ for attached body parts. Pick deliberately.”

Mirror also affects pinned sprites: a pinned sword on a player will mirror with the player by default. Combine with the asymmetric-hitbox advice from the mirror post.