Lottie Support

The list below shows the major features supported by the latest ThorVG Lottie.

Features

Shapes	Description
`Ellipse`	Circle / Ellipse
`Group`	Element Grouping
`Path`	Path Shape
`Polystar`	Polystar / Polygon
`Rectangle`	(Rounded) Rectangle

Strokes	Description
`Dashes`	Dashed stroke style
`MiterLimit`	Miter extension limit size
`Offset`	Dash offset position
`StrokeCap`	Butt / Round / Square
`StrokeJoin`	Miter / Bevel / Round
`Width`	Stroke width

Fills	Description
`Color`	Solid color
`Opacity`	Fill opacity
`Fill Rule`	NonZero / EvenOdd
`Linear Gradient`	Linear gradient fill
`Radial Gradient`	Radial gradient fill

Images	Description
`Embedded`	Base64 embedded image
`Path`	Local / URL image sources
`Formats`	JPG, PNG, WebP

Transforms	Description
`Anchor Point`	Anchor position
`Auto Orient`	Direction-based orientation
`Opacity`	Transform opacity
`Parenting`	Relative transformation hierarchy
`Position`	(Separate) X / Y coordinates
`Scale`	X / Y scale factors
`Skew`	Skew transformation

Interpolators	Description
`Linear`	Linear interpolation
`Bezier`	Cubic Bezier interpolation
`Hold`	Step / hold interpolation
`Spatial Bezier`	Position-based Bezier curve
`Rove Across Time`	Auto-smooth keyframes over time

Modifiers	Description
`Offset Path`	Offset applied to shape paths
`Repeater`	Repeat shape drawing with transforms
`Roundness`	Corner rounding for shapes
`TrimPath`	Trim path individually or simultaneously

Masks	Description
`Add`	Add masking
`Darken`	Darken blend mask
`Difference`	Difference masking
`Expansion`	Mask offset expansion
`Intersect`	Intersect masking
`Lighten`	Lighten blend masking
`Opacity`	Alpha-based masking
`Path Masking`	Path-based clipping
`Subtract`	Subtract masking

Mattes	Description
`Alpha`	(Inverted) alpha blend masking
`Luma`	(Inverted) grayscale blend masking

LayerEffect	Description
`Fill`	Replace fill color
`Drop Shadow`	Drop shadow effect
`Expression Control`	Effect control via expressions
`Gaussian Blur`	Gaussian blur effect
`Stroke`	Stroke modifications
`Tint`	Tinting with single color
`Tritone`	Tinting with three colors

Text	Description
`Alignment Options`	Char / Word / Line / All alignment
`Caps`	Regular, AllCaps, SmallCaps
`Document`	Default text metrics & layout
`Fonts`	Local / URL fonts supported
`Glyphs`	Embedded glyphs
`Justify`	Horizontal text alignment
`Outline`	Text outline
`Range Selector`	Style range within text
`Text Path`	Text along a path
`Tracking`	Character spacing (tracking)

Others	Description
`Expressions`	Lottie scripting (JavaScript-based)
`Markers`	Named animation time markers
`Precomps`	Pre-composition layers
`Time Remap`	Time remapping for animations
`Time Stretch`	Stretching animation duration
`Slots`	Property overriding (slots)

Expressions

Overall Support Rate: 75% (72% fully supported + 3% partially supported)

1. Global Properties

Property	Type	Description	Status
`time`	number	Current time in seconds	✅
`comp(name)`	function	Get composition by name	✅
`thisComp`	object	Current composition reference	✅
`thisLayer`	object	Current layer reference	✅
`thisProperty`	object	Current property reference	✅
`footage(name)`	function	Get footage by name	❌
`fromCompToSurface`	function	Convert comp coordinates to surface	❌
`createPath`	function	Create path programmatically	❌
`posterizeTime(fps)`	function	Posterize time by FPS	❌
`value`	various	Current property value	✅
`index`	number	Layer index	✅

2. Composition (thisComp) Properties

Property	Type	Description	Status
`width`	number	Composition width	✅
`height`	number	Composition height	✅
`duration`	number	Composition duration in seconds	✅
`frameDuration`	number	Duration of one frame (1/frameRate)	✅
`name`	string	Composition name	✅
`layer(index/name)`	function	Get layer by index or name	✅
`numLayers`	number	Total number of layers	✅
`marker`	object	Marker access	❌
`marker.key(index)`	function	Get marker by index	❌
`marker.key(name)`	function	Get marker by name	❌
`marker.nearestKey(t)`	function	Get nearest marker at time	❌
`marker.numKeys`	number	Total marker count	❌
`activeCamera`	object	Active camera reference	❌
`ntscDropFrame`	boolean	NTSC drop frame mode	❌
`displayStartTime`	number	Display start time	❌
`shutterAngle`	number	Motion blur shutter angle	❌
`shutterPhase`	number	Motion blur shutter phase	❌
`bgColor`	array	Background color	❌
`pixelAspect`	number	Pixel aspect ratio	❌

3. Layer (thisLayer) Properties

Property	Type	Description	Status
`width`	number	Layer width	✅
`height`	number	Layer height	✅
`index`	number	Layer index	✅
`parent`	object	Parent layer reference	✅
`hasParent`	boolean	Whether layer has parent	✅
`inPoint`	number	Layer in point (start frame)	✅
`outPoint`	number	Layer out point (end frame)	✅
`startTime`	number	Layer start time in seconds	✅
`hasVideo`	boolean	Whether layer has video	❌ *
`hasAudio`	boolean	Whether layer has audio	❌ *
`enabled`	boolean	Whether layer is enabled	✅
`audioActive`	boolean	Whether audio is active	❌ *
`transform`	object	Layer transform properties	✅
`timeRemap`	property	Time remapping property	✅
`name`	string	Layer name	⚠️ **
`content(name)`	function	Get content by name	✅
`effect(name/index)`	function	Get effect by name or index	✅
`toComp(point)`	function	Convert point to comp space	✅
`sampleImage(...)`	function	Sample image at point	❌
`audioLevels`	property	Audio level in decibels	❌

* Always returns false or 0
** Commented out due to JerryScript conflict issue

4. Transform Properties

Property	Type	Description	Status
`anchorPoint`	array[2]	Anchor point coordinates	✅
`position`	array[2]	Position coordinates	✅
`scale`	array[2]	Scale percentages	✅
`rotation`	number	Rotation in degrees	✅
`opacity`	number	Opacity (0-100)	✅

5. Property Methods

Method	Parameters	Description	Status
`value`	-	Current property value	✅
`valueAtTime(t)`	time	Value at specific time	✅
`velocity`	-	Current velocity	❌ *
`velocityAtTime(t)`	time	Velocity at specific time	✅
`speed`	-	Current speed	❌ *
`speedAtTime(t)`	time	Speed at specific time	✅
`wiggle(freq, amp, ...)`	various	Randomize property value	✅
`temporalWiggle(...)`	various	Time-based wiggle	✅
`loopIn(type, numKeys)`	type, count	Loop before first keyframe	⚠️ **
`loopOut(type, numKeys)`	type, count	Loop after last keyframe	⚠️ **
`loopInDuration(...)`	type, time	Loop in by duration	⚠️ **
`loopOutDuration(...)`	type, time	Loop out by duration	⚠️ **
`key(index)`	index	Get keyframe by index	✅
`key(markerName)`	name	Get keyframe by marker	❌
`nearestKey(t)`	time	Get nearest keyframe at time	✅
`numKeys`	-	Total keyframe count	✅
`propertyIndex`	-	Property index	✅
`propertyGroup(level)`	level	Get property group	⚠️ ***
`smooth(...)`	various	Smooth property value	❌

* Returns 0 by default
** Only "cycle" and "pingpong" modes supported
*** Only level 1 supported

Loop Types

Type	Constant	Status
Cycle	`"cycle"`	✅
Ping Pong	`"pingpong"`	✅
Offset	`"offset"`	❌ *
Continue	`"continue"`	❌ *

* Logged as not supported

6. Math Functions

Function	Parameters	Description	Status
`add(a, b)` / `$bm_add`	values	Addition (1D, 2D, string)	✅
`sub(a, b)` / `$bm_sub`	values	Subtraction (1D, 2D)	✅
`mul(a, b)` / `$bm_mul`	values	Multiplication (1D, 2D)	✅
`div(a, b)` / `$bm_div`	values	Division (1D, 2D)	✅
`sum(a, b)` / `$bm_sum`	values	Sum (same as add)	✅
`clamp(v, min, max)`	value, limits	Clamp value between limits	✅
`linear(...)`	various	Linear interpolation	✅
`ease(...)`	various	Cubic ease interpolation	✅
`easeIn(...)`	various	Ease in interpolation	✅
`easeOut(...)`	various	Ease out interpolation	✅
`random()`	-	Random value (0.0-1.0)	✅
`degreesToRadians(deg)`	degrees	Convert degrees to radians	✅
`radiansToDegrees(rad)`	radians	Convert radians to degrees	✅
`lookAt(from, to)`	points	Calculate rotation to look at	❌

7. Vector Math Functions

Function	Parameters	Description	Status
`dot(vec1, vec2)`	vectors	Dot product	✅
`cross(vec1, vec2)`	vectors	Cross product (2D → scalar)	✅
`normalize(vec)`	vector	Normalize vector	✅
`length(vec)`	vector	Vector length/magnitude	✅

8. Shape/Path Properties

Property	Type	Description	Status
`path`	object	Path object	✅
`points()`	function	Get path points	✅
`pointOnPath(progress)`	function	Get point at progress (0-1)	✅
`inTangents`	array	Path in tangent points	❌
`outTangents`	array	Path out tangent points	❌
`isClosed`	boolean	Whether path is closed	❌

9. Content/Group Methods

Method	Description	Status
`content(name)`	Get content by name	✅
Group support	Group objects	✅
Path support	Path objects	✅
Polystar support	Polystar objects	✅
Trimpath support	Trimpath objects	✅

Polystar Properties

Property	Type	Description	Status
`position`	array[2]	Polystar position	✅
`innerRadius`	number	Inner radius	✅
`outerRadius`	number	Outer radius	✅
`innerRoundness`	number	Inner corner roundness	✅
`outerRoundness`	number	Outer corner roundness	✅
`rotation`	number	Rotation in degrees	✅
`points`	number	Number of points	✅

Trimpath Properties

Property	Type	Description	Status
`start`	number	Trim start percentage	✅
`end`	number	Trim end percentage	✅
`offset`	number	Trim offset	✅

10. Effect Properties

Method	Parameters	Description	Status
`effect(name/index)`	identifier	Get effect by name or index	✅
Effect property access	name	Get effect property by name	✅

11. Adobe ADBE Reserved Keywords

Keyword	Description	Status
`ADBE Root Vectors Group`	Root vectors group	✅
`ADBE Vectors Group`	Vectors group	✅
`ADBE Vector Shape`	Vector shape path	✅

Known Limitations

1. Loop Mode Restrictions

✅ Supported: "cycle", "pingpong"
⚠️ Not supported: "offset", "continue" (logged only)

2. PropertyGroup Limitation

Only propertyGroup(1) is supported
Higher levels return undefined

3. Audio Properties

All audio-related properties return default values (false or 0)
No actual audio processing