Track Types Overview

Texturge’s Sequencer integration stores UGlyphAnimation keyframe curves through dedicated track types. The track system is defined in Plugins/Texturge/Source/Texturge/Public/Animation/Tracks/.

Track Class Overview

Class	Base class	Description
UMovieSceneGlyphAnimationTrack	UMovieSceneNameableTrack	glyph animation main track, manages multiple typed sub-tracks
UMovieSceneGlyphAnimationSection	UMovieSceneSection	sub-track section, one per track type
UMovieSceneTextAnimationSection	—	type alias (using = UMovieSceneGlyphAnimationSection), legacy asset serialization compatibility only
FTextAnimationSubTrackData	USTRUCT	sub-track data (track type + display name + Float channel array)
FTextAnimationTrack	USTRUCT	legacy track type (@deprecated, kept for compatibility)
ETextAnimationTrackType	UENUM	track type identifier (10 types)

UMovieSceneGlyphAnimationTrack

The main track class carrying all of UGlyphAnimation’s sub-tracks:

• Internally holds a Sections array (each UMovieSceneGlyphAnimationSection corresponds to a sub-track of one track type) plus a hidden LayoutHelper layout helper section
• AddSubTrack(ETextAnimationTrackType, FName) / RemoveSubTrack(int32) — add / remove typed sub-tracks
• SupportsMultipleRows() returns true; each sub-track occupies its own row
• GetLocalizedSubTrackDisplayName(FName) — localized sub-track display names
• RenumberRows / SyncLayoutHelper — internal row renumbering and layout helper maintenance

UMovieSceneGlyphAnimationSection

Sub-track section whose core data is FTextAnimationSubTrackData SubTrack:

• SetSubTrackData(ETextAnimationTrackType, const FName&) — set the sub-track type and display name
• GetSubTrackDataMutable() — mutable access (curve editing)
• CacheChannelProxy() — registers Channels into the Sequencer channel proxy (keyframe editing entry)
• LinkedTrackId (FGuid) — link identifier to the legacy text animation track

NOTE

UMovieSceneTextAnimationSection is a using type alias of UMovieSceneGlyphAnimationSection in the source (MovieSceneTextAnimationSection.h contains only this declaration), kept for deserializing legacy assets. New code uses UMovieSceneGlyphAnimationSection directly.

Sub-Track Data Structure

FTextAnimationSubTrackData stores 1–4 FMovieSceneFloatChannels per track type:

Track type	Channels	Channel suffixes	Default key value
Opacity	1	(none)	1.0
LetterSpacing	1	(none)	0.0
Rotation	1	(none)	0.0
Translation	2	X / Y	0.0
Scale	2	X / Y	1.0
Shear	2	X / Y	0.0
Pivot	2	X / Y	0.5
ShadowOffset	2	X / Y	0.0
Color	4	R / G / B / A	1.0
ShadowColor	4	R / G / B / A	0.0

The channel count is determined by FTextAnimationSubTrackData::GetChannelCount(ETextAnimationTrackType) (Float→1, Vector2D→2, Color→4).

Animation Channels (21 Channels)

The 10 track types expand into 21 curve channels, corresponding to FPerLayerCurves’s 21 TArray<FRichCurveKey>s and the properties of FGlyphAnimationState:

Transform (3 Float + 10 Vector2D components)

Track type	Channels	State property	Description
Opacity	Curve_Opacity	Opacity	opacity (default 1.0)
LetterSpacing	Curve_LetterSpacing	LetterSpacing	letter spacing (pixels)
Rotation	Curve_Rotation	Rotation	rotation (degrees)
Translation	Curve_TranslationX / Y	PositionOffset.X / Y	position offset (pixels)
Scale	Curve_ScaleX / Y	Scale.X / Y	scale (default 1.0)
Shear	Curve_ShearX / Y	Shear.X / Y	shear transform
Pivot	Curve_PivotX / Y	Pivot.X / Y	pivot (default 0.5)
ShadowOffset	Curve_ShadowOffsetX / Y	ShadowOffset.X / Y	shadow offset (pixels)

Color (8 Color components)

Track type	Channels	State property	Description
Color	Curve_ColorR / G / B / A	Color.R / G / B / A	tint: RGB = tint color, A = tint share (0–1)
ShadowColor	Curve_ShadowColorR / G / B / A	ShadowColor.R / G / B / A	shadow color

NOTE

Color.A in channels is the tint share, not opacity — the identity value is Transparent (0,0,0,0); untinted channels do not participate in multiplication (always-0 would break multiply blending; the evaluator uses additive stacking instead). Glyph opacity is controlled separately by the Opacity channel.

Curve Extraction

UGlyphAnimation keyframe curves are extracted during baking:

Function	Description
FAnimationCompiler::ExtractCurves(const UGlyphAnimation*)	extracts and returns FGlyphCurveSet (21 FRichCurves)
FAnimationCompiler::ExtractCurvesRef(const UGlyphAnimation*)	zero-copy reference extraction (UGlyphAnimation internally caches CachedExtractedCurves + fingerprint)

Extraction caches on GetSignature() of all Tracks/Sections in the MovieScene — Sequencer edits only update Section signatures, so all sub-objects must be traversed (see”Bake Pipeline”).

Timing Modes

Playback timing is controlled by UTextAnimator’s EPlaybackMode (tracks carry no timing mode):

Mode	Description
Duration	uniform playback over the total duration
CPS	driven by glyphs revealed per second, CPS floor 1.0

Track Editor

FGlyphAnimationTrackEditor (TexturgeEditor module, Private/TrackEditors directory) extends FMovieSceneTrackEditor:

• Renders glyph animation tracks and typed sub-tracks in the Sequencer UI
• Handles sub-track section creation, dragging, and resizing
• The static callback OnSubTrackAddedToSequencer(ETextAnimationTrackType) syncs new sub-tracks back to the Blueprint
• Available in editor builds only; not packaged into runtime

Play Direction

EPlayMode defines the layer-level play direction (FPerLayerCurves::PlayDirection):

Enum value	Description
Forward	forward playback
Reverse	reverse playback
PingPong	alternating forward/reverse playback

EStagePlayDirection offers the same three options at stage granularity (UTextAnimationStageController). Loop count is controlled independently by FPerLayerCurves::NumberOfLoops (0 = infinite loop).