How to Make Meshes Pop in Unreal Engine: Pop-In, Squash & Stretch, Wobble

A mesh that simply appears feels dead. The same mesh that springs up from nothing, overshoots its size, and settles with a tiny squash feels alive, and players read that as quality. This is the heart of “game juice”: short, snappy, secondary motion layered on top of things that would otherwise just sit there.

This guide covers the practical ways to get that pop in Unreal Engine, what each one costs you, and when to reach for which. Three of them are built into the engine and free. The fourth is a plugin I make, Spline Juice, and I will be upfront about where it fits and where the built-in tools are the better call.

What “pop” usually means

When people ask how to make meshes pop, they tend to mean one of three things:

1. Pop-in on spawn. A pickup, a loot drop, a placed building, or a UI-style 3D element appears with an overshoot and a settle instead of blinking into existence.
2. Life in a static scene. Props and scenery that never move get a little secondary motion: a breathing pulse, a jelly wobble, a machine whirring in place.
3. A build or reveal moment. A mesh assembles itself from pieces, grows out of the ground, or melts away.

All three are the same underlying idea: animate the mesh’s shape or scale over a fraction of a second with an overshoot curve. The question is where that animation lives: on the actor’s transform, in the material, or in a tool that manages it for you.

Method 1: Timeline + scale curve

The quickest pop-in, and the one to reach for when you need it on exactly one actor.

1. Open the actor’s Blueprint and add a Timeline node, driven from Event BeginPlay into Play from Start.
2. Inside the Timeline, add a float track named Scale, set the length to 0.35, and add four keys: (0.00, 0.01), (0.20, 1.20), (0.28, 0.92), (0.35, 1.00). Right-click the keys and set them to Auto so the curve eases through the overshoot.
3. From the Timeline’s Update pin, call Set Actor Scale 3D (or Set Relative Scale 3D on the mesh component) and feed it a Make Vector with Scale in X, Y, and Z.

Start at 0.01 rather than 0: a zero scale can trip collision warnings. For a squash on landing, add a second track and drive Z with it while X and Y get 1 / sqrt(Squash), which keeps the volume roughly constant so the mesh reads as squashing rather than shrinking.

The trade-offs. This scales the real transform. Collision, overlap events, and anything attached to the actor scale right along with it, so a pickup that pops in can briefly overlap the player at 1.2x size. It can only scale: the mesh cannot bend, bulge in one spot, wobble tip-first, or melt. And it lives in each actor’s Blueprint, so fifty different props mean fifty copies of the logic (or a shared component you now maintain).

Method 2: Material World Position Offset

World Position Offset (WPO) moves vertices in the material at render time only. The actor, its transform, and its collision never move, which is exactly what you want for a purely cosmetic flourish.

A pop-in in the material. Subtract Object Position from Absolute World Position to get each vertex relative to the pivot (call it Rel). Multiply Rel by (PopScale - 1) and plug the result into World Position Offset. At PopScale = 0 the mesh collapses to its pivot; at 1 it is untouched. Drive PopScale from Blueprint by creating a Dynamic Material Instance on BeginPlay and calling Set Scalar Parameter Value from the same Timeline curve as Method 1.

A wobble for idle life. A Custom node gives you a sway that moves the top more than the base:

// Inputs: Rel (float3: Absolute World Position - Object Position),
//         Time, Amp, Freq, Height
float h = saturate(Rel.z / Height);          // 0 at the pivot, 1 at the top
float sway = sin(Time * Freq) * Amp * h * h; // tip moves more than the base
return float3(sway, 0, 0);                   // sway along world X

Do the subtraction with regular nodes before the Custom node, so the HLSL only sees a small float3 instead of large world coordinates. Add the output to anything else already feeding World Position Offset.

The trade-offs. You edit every material the effect should run on (a Material Function helps, but it still has to be wired into each master material). WPO that pushes vertices outside the mesh’s bounds gets culled, so you raise the component’s Bounds Scale to compensate. A parameter you set from Blueprint does not produce motion vectors on its own, so under TAA or TSR the mesh smears and ghosts until you add a previous-frame evaluation through a PreviousFrameSwitch. And on an animated skeletal mesh the pivot-relative math runs on already-skinned vertices, so height- or pivot-based effects drift with the pose.

If you want to go deep on this route, I wrote a full build-along for squash and stretch along a spline with World Position Offset, including the motion-vector fix.

Method 3: Sequencer

For a one-off hero moment, such as a cinematic reveal or a trailer shot, a Level Sequence is the most art-directable option. Key the actor’s scale, or key a material parameter track that drives a WPO effect from Method 2, and scrub it frame by frame with the curve editor.

The trade-offs. It is keyframed per shot, so it does not scale to dozens of props or to things that spawn at runtime. Transform keys have the same collision behavior as Method 1. A build or assemble reveal done this way usually means hand-animating pieces, or reaching for a Chaos Geometry Collection, both of which are heavy for a moment that is purely cosmetic.

Method 4: Ready-made presets with Spline Juice

Full disclosure: Spline Juice is my plugin. It exists because I kept rebuilding Method 2 for every project. It packages the WPO approach (collision never moves, motion vectors handled, bounds expanded while it plays) behind an editor panel, and ships the common motions as presets. It works on any static mesh and on animated skeletal meshes, needs no material editing and no C++, and supports Unreal Engine 5.1 to 5.8.

Getting a pop-in on a mesh:

1. Right-click the mesh actor in the level viewport and choose Spline Juice > Add Deform Component. It works on a whole selection at once.
2. On the Meshes & Materials tab, click Generate Deform Materials. It authors a deform-capable copy of each material and leaves your originals untouched, so you never open the material editor.
3. On the Presets tab, pick Pop In (Spawn) and click Apply.
4. Switch on Live Preview to see it in the viewport without pressing Play. In game it runs on Auto Play, or you trigger it from Blueprint.

The presets map onto the three kinds of pop from the top of this guide:

• Pop-in and spawn: Pop In, Grow From Ground, Rain Drops, Overshoot, and a Bounce Settle modifier you can add to any preset.
• Life in a static scene: Idle Breathe, Wobble (Jello), Balloon Up, Gulp, Rumble, and Whirring.
• Build and reveal: Cannon Burst (the mesh shatters into pieces, tumbles, and reassembles as it lands) and Goo Drip (a slow melt into a puddle), plus Squash & Stretch, Bouncy Balls, Cannon, and Follow Path for motion and impact.

Because the deform layers on top of the playing animation, it works on characters too, not just props:

And for build moments, a static mesh can explode into pieces and settle back together as it travels:

Every preset stays editable after you apply it (the spline, the timing, and the squash, wobble, inflate, melt, and bulge curves), and Group Stagger plays a whole selection as one wave instead of all at once. The Presets documentation describes each one.

The trade-offs. It is a paid plugin on FAB, where the built-in methods are free. It deforms shape and scale; it does not do outlines, glows, or hover highlights. It is visual only, so if you want collision to grow with the mesh, Method 1 is the right tool. And the assembly effect is static-mesh only.

Side by side

	Timeline scale	Material WPO	Sequencer	Spline Juice presets
Collision stays put	No	Yes	No (transform keys)	Yes
Bends, squashes, wobbles the shape	Scale only	Yes, hand-written	Scale, or via material params	Yes, 16 presets
No material editing	Yes	No, every material	Yes (transform keys)	Yes, generated for you
Animated skeletal meshes	Uniform scale only	Tricky	Uniform scale only	Yes
Reuse across many actors	Per Blueprint	Per material	Per shot	Per selection, as a wave
Setup time	Minutes	An hour or more	Minutes per shot	Seconds
Cost	Free, built in	Free, built in	Free, built in	Paid (FAB)

Which should you use?

• One actor, simple uniform pop, and collision growing is fine: the Timeline. It is five minutes of work and nothing to install.
• A specific shader effect on a handful of materials, and you want full control of the math: hand-written WPO. Budget time for bounds and motion vectors.
• A single cinematic moment: Sequencer.
• Lots of props, animated characters, several kinds of motion, or no appetite for material work: Spline Juice gets you there in seconds per mesh.

Whichever you pick, the rule that makes it read as “juice” is the same: overshoot, then settle. A pop that lands exactly on its final size looks mechanical; one that goes about 20 percent past and eases back looks alive.