Move It! Glide an Entity to a Target Over Time

Welcome to Scene Graph: Animation. In the Verse Scene Graph series you learned what entities and components are, how they hang off each other in a tree, and that every entity carries a transform — its position, rotation, and scale. That was the still photograph. This series is the movie: we're going to make things move.

We'll do it the way real games do — not by teleporting things frame by frame, but by handing the engine a short animation and letting it play. By the end of these four lessons you'll have built a moving platform a player can ride. This first lesson is the foundation: glide one thing smoothly from where it is to somewhere new.

We'll set everything in an Art Deco bank vault — gold-capped pillars, a teller wall, and a polished marble floor — and animate the vault's contents.

The one idea: a transform is "where a thing sits"

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Transform Bundle

Everything that moves, moves its transform. A transform bundles three facts:

• Translation — where it is (a vector3 of Left, Up, Forward)
• Rotation — which way it faces
• Scale — how big it is

You can read the current transform off any entity. Notice the axis names — Fortnite uses Forward, Left, and Up, not X/Y/Z:

# The transform is just three facts about where a thing sits:
# where (Translation), which way it faces (Rotation), and how big (Scale).
Here := Entity.GetLocalTransform()
Forward := Here.Translation.Forward
Up := Here.Translation.Up
Left := Here.Translation.Left

GetLocalTransform() uses round brackets — it can't fail, it always hands back a transform (the identity transform if the entity has no transform_component yet). That bracket-shape rule is exactly the one from The Grammar of Verse: round brackets never fail, square brackets can.

Don't move things by hand — let the mover do it

You could nudge an entity every tick with SetLocalTransform. But hand-animating is fiddly and easy to get wrong. The Scene Graph ships a purpose-built tool: the keyframed movement component.

A keyframed movement component plays a list of keyframe deltas for an entity. Each delta says: "change the transform THIS much, over THIS many seconds, with THIS easing." You describe the motion once; the engine animates it for you.

You add this component to an entity in the editor (select the entity → Add Component → Keyframed Movement), then your code finds it and presses Play. That split — component in the editor, behavior in code — is the whole Scene Graph philosophy.

Glide a safe across the vault

Here's the complete component. Bolt it onto the vault's safe (which also has a Keyframed Movement component), and when the round begins, the safe glides forward and eases to a stop:

Read it top to bottom:

1. OnBeginSimulation runs once when the component wakes up in the game. We call (super:)OnBeginSimulation() first so the base component does its own setup — always be a polite subclass.
2. Entity.GetComponent[keyframed_movement_component] asks "is there a mover on me?" The square brackets mean it can fail; the if guards it. No mover → nothing to do.
3. The delta is the heart of it. Duration is how long; Easing shapes the speed curve (more on that next); Transform.Translation says move 500 units forward — relative to the start, not an absolute spot in the world.
4. SetKeyframes loads the list. We pass oneshot_keyframed_movement_playback_mode{} — play once and stop.
5. Play() starts it. The engine handles every frame from here.

Easing: the difference between "robotic" and "alive"

The Easing value decides how the speed changes across the move:

• linear_easing_function{} — constant speed. Mechanical, like a conveyor.
• ease_in_out_cubic_bezier_easing_function{} — starts slow, speeds up, slows to a stop. This is what real, weighty objects do, and it's why our safe feels heavy instead of teleport-y.

Swapping one word changes the whole feel of the motion. That's the payoff of letting the mover animate for you.

"Relative" is your friend

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Relative Motion

Because the delta's translation is relative, this one component works on any entity, anywhere in the vault — it always moves 500 units forward from wherever it starts. You never hard-code world coordinates. Drop the safe anywhere, the glide just works.

Recap

• A transform is position + rotation + scale; moving something means changing its transform.
• The keyframed movement component animates an entity for you — you describe keyframe deltas, it plays them.
• A delta = Duration + Easing + a relative Transform.
• SetKeyframes(..., oneshot...{}) then Play() runs it once.
• Easing turns stiff motion into believable motion — ease_in_out for weight, linear for machines.

Next up — Part 2: Spin to Win — we keep the entity in place and turn it instead, and meet a subtle gotcha about rotations taking the shortest path.