GS_Motion

Track-based animation and tween system — abstract base classes for motions, tracks, composites, assets, and proxies with a domain extension pattern.

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GS_Motion is the framework’s central track-based animation system. It defines abstract base classes that domain gems extend with concrete track types — GS_UI extends it with 8 UI animation tracks (.uiam assets), and GS_Juice extends it with 2 feedback tracks (.feedbackmotion assets). The system handles playback timing, per-track easing, proxy-based entity targeting, and deep-copy runtime instancing from data assets.

For usage guides and setup examples, see The Basics: GS_Core.

Architecture
Core Classes
Domain Extensions
Extension Pattern
See Also

Architecture

GS_MotionTrack (abstract base)
    ├── UiMotionTrack (GS_UI domain base)
    │       ├── UiPositionTrack
    │       ├── UiScaleTrack
    │       ├── UiRotationTrack
    │       ├── UiElementAlphaTrack
    │       ├── UiImageAlphaTrack
    │       ├── UiImageColorTrack
    │       ├── UiTextColorTrack
    │       └── UiTextSizeTrack
    └── FeedbackMotionTrack (GS_Juice domain base)
            ├── FeedbackTransformTrack
            └── FeedbackMaterialTrack

GS_MotionAsset (abstract base)
    ├── UiAnimationMotionAsset (.uiam)
    └── FeedbackMotionAsset (.feedbackmotion)

GS_MotionComposite (runtime instance)
    └── Created by asset's CreateRuntimeComposite()

Core Classes

Class	Description	Page
GS_MotionTrack	Abstract base for all animation tracks — fields, lifecycle, virtual methods, extension guide.	MotionTrack
GS_Motion	Playback engine — ticks tracks, computes per-track progress windows, applies easing, manages lifecycle.	Motion Engine
GS_MotionComposite	Runtime deep-copy instance with proxy entity overrides — created from GS_MotionAsset.	MotionComposite
GS_MotionAsset	Abstract base for motion data assets — holds track definitions and creates runtime composites.	MotionAsset
GS_MotionProxy	Serialized struct for track-to-entity redirection — allows designers to target named tracks at different entities.	MotionProxy

Domain Extensions

GS_Motion is designed to be extended by domain gems. Each domain creates its own track hierarchy, asset type, and file extension.

Domain	Gem	Base Track	Concrete Tracks	Asset Extension
UI Animation	GS_UI	`UiMotionTrack`	Position, Scale, Rotation, ElementAlpha, ImageAlpha, ImageColor, TextColor, TextSize (8)	`.uiam`
Feedback	GS_Juice	`FeedbackMotionTrack`	FeedbackTransformTrack, FeedbackMaterialTrack (2)	`.feedbackmotion`

Extension Pattern

To create a new motion domain:

Create a domain base track — class MyTrack : public GS_Core::GS_MotionTrack
Create concrete tracks extending the domain base — each overrides Update(float easedProgress) and GetTypeName()
Create a domain asset — class MyAsset : public GS_Core::GS_MotionAsset with vector<MyTrack*> m_tracks
Create an instance wrapper struct (not a component) — holds Asset<MyAsset> + vector<GS_MotionProxy>, manages Initialize / Unload / Play / Stop
Embed the wrapper — components embed the instance wrapper struct as a serialized field

Critical: All track vectors must use raw pointers: vector<MyTrack*>. Never use unique_ptr — O3DE SerializeContext requires raw pointers for polymorphic enumeration in the asset editor.

Get GS_Core

GS_Core — Explore this gem on the product page and add it to your project.