GSOC-2019::Export Animation for Web



Any tips or sources that will help me understand lottie better?




I also recommend to read all comments here -


Thank you :slightly_smiling_face:


Thank you :slight_smile:


Is it okay If I start documenting the mappings done till now at synfig-docs-dev?


Great idea! I have created a page at
Please feel free to edit it as you like. :slight_smile:


I will get started with it then! :grinning:


@KonstantinDmitriev, I have created a PR for documentation. Please have a look at it. :slight_smile:


Am I right to assume that only hold interpolations are present for the points parameter in star layer?
I tried experimenting with it, the only behaviour I could reproduce was hold/constant.
@BobSynfig any inputs would be appreciated :smile:


Lottie does not support animation for change between polygon/star parameter for the star layer. To support it, my suggestion:
whenever the polygon parameter is true, I will change the inner radius of the star such that the star looks like a regular polygon. (Mathematically: inner radius = outer radius * Cos(theta/2); theta = 360/Number of points)
Please give your input on this. If ok, I will start working on it.


Yes, this is good solution! :slight_smile:


This is not really a hold interpolation. The points parameter has integer type, so it will change non-smoothly.


…Here is an example:


(blue star uses Linear interpolation, red star uses Constant interpolation).

Source file - star-ponts.sifz (1017 Bytes)


BTW, after looking at Graphs panel, I have found that change of Points parameter is not really linear -

This looks like bug, I have filled an issue for that -


Yes, This seems to be a bug. For now, I will leave this points interpolation and work on animation of polygon/star parameter.
Thank you! :smiley:


This task seems to be much difficult than what I thought of. I need insert and remove waypoints from the animation to achieve this. So I am devising an algorithm to take care of all the corner cases.
In the mean time, I will also start working on other layers for a good progress.
So this marks the finish of star layer. I have tested it from my side and everything seems ok till now.
@KonstantinDmitriev could you test this layer? Please inform if anything seems off.


You right, if inner radius is animated, then your code should take this into account and modify/replace waypoints in time segments where polygon parameter changes.

I will test the exporter for Star Layer and get back with my feedback. :slight_smile:

What layer type you would like to implement next?


I will get started with circle layer?
Also should push this new layer’s work on the same PR? Or a new pull request?


Circle layer - good. :slight_smile:

Let’s use the same PR. Just rename it accordingly. :slight_smile: