Splines. managing thickness

This is my first animation test. Made out of 5 simple splines. Just a wink to say ‘hello’.
I used advanced spline to connect the eyes to the lower spline.

As you can see, it lacks some line thickness management. I tried the thickness handle, but I would need to add some thickness handle without tangent and radius handle, and so far, I haven’t found out how…

I looked how to manage thickness of Spline lines. I toggled thickness handle. I see 2 handles by spline, so I can’t get a spline line to start thin, grow larger and finally shrink thin again.
The best way would be to have the ability to had a thickness handle, but I found no such feature.
I worked with two separate splines I joined, then linked the thickness radius of two handles, and finally moved both handle so that they merge. Here’s an example of the result. It is ok, but it fells clumsy. Plus I had to link the tangent of the to spline so that I get a smooth spline. As you can see, I still have some glitch in the thickness.
It feels quite complicated, plus I think that so many parameters can lead to uncontrolled behavior when transforming the spline in order to create an animation.

*Isn't there a better way to simply had a thickness handle ?*

You can add new width/thickness handle by right-clicking on one and select “Insert new Item”.

Thank you. But still, this is not exactly what I am looking for. I just realized something, so I’ll try to be more acurate :

It seems there’s a major difference between outline spline and advanced outline spline regarding thickness control.

Here I drew two quite similar shapes using splines : on the right is an advanced spline.

With a regular spline, each position handle is also a thickness handle. So inserting an item is a new thickness handle. But also a position handle, so even if you insert and keep the shape when you modify the curve, you have to manage the position handle.

With an advanced spline, whatever number of position handle you used, you only get two thickness handles that you can slide along the spline keeping the curvature unchanged. So you can modify thickness along the spline. But there are only two handle and the thickness can only be changed between the two handle, then it is constant to the end of the spline.

So it seems that advanced splines can only have 2 thickness handle, but those are disconnected from position/tangent handle, whereas splines have thickness handles linked to position/tangent handles. Am I right ?

I think what rodolforg meant with

You can add new width/thickness handle by right-clicking on one and select “Insert new Item”.

is by right clicking the center point of the handle and select “Insert New Item”.
By right-clicking on one of the paler purple points which are located at the center of each width handles, you should be able to find the option for it, along with many more options that are only available on adv. outlines.

Please note that the newly added width handles will be placed in a certain spot. It’s really difficult to explain, but it’s like at the halfway between the width point you right-clicked on and the next width point (sorry, I’ve tried my best ._.v).

For the normal outlines, yes, the width handles are strictly linked to each vertex points (the orange dots). As for the adv. ones… well… sort of.

As mentioned before, you can add more thickness handle even in adv. outlines. But you’re right, these handles are independent to the adv. outline they’re tied on, meaning you can move their locations freely along the outlines by simply dragging those pale purple dots around.

They have their own pros and cons, mostly due to simplicity and freedom on designing the lines.
Using normal outlines will give you easier time on keeping the width points in place. But advanced outlines should be able to help better on drawing complicated lines with as low amount of vertex points as possible, at least imho.

1 Like

Great !
I hadn’t thought of right clicking a thickness handle. The more I dig in SynFig the more I find terrific features. Thank you so much guys.

1 Like