Layer usage - considerations

The transforming layers (translate, rotate & scale) do things to a set of layers,
that can be done to those individually using the tools (scale, rotate & smooth move) as well.

When should we use layers instead?
Just if it seems convenient to us, the users?
Is there any performance consideration?

Using the tools lets us select individual ducks or areas of ducks on a layer, rather than affecting the entire layer.

I typically use the tools when I’m drawing or tracing artwork, and use the layers when animating it.

I use the tools to when I want to animate shapes without splitting the shape into pieces.

When I’m animating an arm one approach is to split the arm into pieces and put each piece on a separate layer - very similar to traditional cut-out animation. In that case I can use the rotate layers working on those pieces to do things like my rotation.

However there are times when it’s better not to do this - particularly when you are trying to emulate traditional cel animation. In that case you can select groups of ducks on each key frame and rotate them using the rotate tool. My joints aren’t “fixed” by my creation of layers and I can create say, an elbow, at any point.

I’ve just done a five minute animation and I haven’t used the rotate layer at all, as it was all done using the rotate tool to rotate ducks on my key frames. However I have done some cut-out animation where I didn’t use the rotate tool at all.

So whether I use the tools or the layers depends on the style of animation I’m trying to do.

Beware that rotate tool does rotate the ducks of the layers but two consecutinve rotations along the time doesn’t produce a rotation in the middle but a translation between the two shapes (the original and the rotated).
For fully interpolable rotation you need to use the rotation layer.

for scale and translate it is fine to use the tool or the layer but remember that when the animation is huhgely complex it is hard to handle to scale all the ducks properly and it it better to use the scale and zoom layers.

Genete, can you please explain your statement a bit more about rotating ducks vs. rotation layer, you lost me…

Thx. OHo.

A duck is that coloured circle you grab and move. Some of them move points on an outline, others change circle size or text size or change a warping, and some… rotate layers.

thank you, I do know what “ducks” are in Synfig, but I didn’t get the point in Genete’s post…

Genete, can you help? I would then be able to add that in the docs as soon as I understand. Thx.

Hi Oho,
The rotate layer works by reading the result of its context (the layers that are behind it inside its canvas scope) and performing a rotation of the result using the value of the angle parameter and the origin parameter as origin of rotation.
So when you are in edition mode and modify the angle of rotation say to 15 degrees, at the frame 1s and afterward you place the cursor time at time 3s and modify the angle to 25 degrees, you obtain two waypoints for the angle parameter.

So by those modifications of the angle parameters you get the animation of a parameter (the angle). Depending on the interpolation default selected and the surrounding waypoints the value of the angle parameter changes between 1s and 3s. For linear interpolation you can find that at time 2s the angle value is 20 degrees.

Accordingly to the variation of the angle, the rotate layer’s context is rotated and so, animated continuously between one and other angle.

On the other hand the Rotate Tool is just a tool to modify many ducks (and so the parameters associated to those ducks) at the same time.
Say you have a complex composition made by lots of layers and you use the rotate tool to rotate them. In that case your not modifying any angle of the underlining layers. You are only editing a bunch of parameters with a tool that handles them in a rotation way. So when you use the rotate tool at the same frames than the previous example and perform modifications of the ducks of the layers you produce waypoints to all those ducks at the corresponding times (1s and 3s in the example).
When you edit the ducks with the rotate tool you just define the start and end positions, and then, Synfig interpolates between them with a straight line, not an arc.

I hope it helped.

Look like the rework of layer/doc involved somes touch in tools :wink:

Has i was seeing you around the layer/doc, i have made a turn around the tools/doc, starting with little [syntax|internal links|presentation|normal tool reference] unification.
More works in unification can be done there : around tools options of the toolboxpanel (in a table like for layers’ ones ?).

And could be useful if we found a place for all this genete special something explanation for both tools and layers / docs.


Use Rotation Layer for Cut Out style animation.Use Toll box tools in animation for Morph style animation.
In conjunction with the layers panel Hierarchy ability Rotate can be used to create arms legs etc. Here is an example I posted Ball joint style construction.[url]Ball joint style construction]

Herb, I have added a tips & triks section in wiki/cutout with zat you explain…fill free to improve it


The tools will transform the coordinates of the points and the handlers (ducks). So you will add waypoints equals to the points and the handlers(ducks) of your shape.

You must always use layers when you wand to transform a layer (Bline – Circle – PasteCanvas – all the scene or everything).
Use the tools when you wand shape deformation not transformation.


e.g. rotation
Tools => waypoints = points + ducks.
Layer => waypoint = angle = 1.

Don’t forget that bline is region or outline. And BLine is a Bezier Curve. The Ducks are the Tangents of the Bezier Point, but for easier use are multiplied by three in the editor and in the save file ( this confused me a lot when I first tried to get data from the save file ).