Outline Layer

Property	Path to Property in lottie
Z depth	Depends on ordering of layers in lottie format
Amount	layers/solid.json -> “ef” -> effects/fill.json -> effects/opacity.json
Blend_method	layers/solid.json -> “bm” -> helpers/blendMode.json
Color	layers/solid.json -> “ef” -> effects/fill.json -> effects/color.json
Origin	Added to vertex list of the polygon
Invert	layers/solid.json -> helpers/mask.json -> “inv”
Antialiasing	This property is always present(true) in lottie.
Feather	Not Supported
Type of Feather	Not supported
Winding Style	Not supported
Vertices	layers/solid.json -> helpers/mask.json -> “pt”
Outline Width	Manipulation of vertices
Expand	Manipulation of vertices
Sharp cusps	Manipulation of vertices
Rounded Begin	Manipulation of vertices
Rounded End	Manipulation of vertices
Loopyness	Not required
Homogeneous	Manipulation of vertices

Important points

• Instead of directly using the shapes layer from Lottie, a solid color layer is used and is masked(using masks) to draw an outline. This is done to support the invert parameter from Synfig.

• The mask is drawn according to: https://github.com/synfig/synfig/blob/678cc3a7b1208fcca18c8b54a29a20576c499927/synfig-core/src/modules/mod_geometry/outline.cpp

• It is possible to export outlines without variable widths. To do so you need to use Outline width as the width for all vertices, upon doing so you can export the outlines without variable widths by choosing the same option from the Export menu.

• In exporting without variable widths, the rounded edges cannot be animated.