How do I make a circle sector and animate it?

I am making an animation and would like to make a circle appear in a clocklike fashion (kind of like how a pacman closes it mouth). However, it seems that Synfig does not have a similar function, or even an easy way to draw a circle sector at all.

Have I missed something among the tools?

Create a conical gradient with the right animated gradient points to create the effect. Then mask it with a circle centered on the gradient origin.

That was one of my ideas except that it would not animate correctly that way.

Please refer to the attached file. The animation is correct when I was just changing the gradient’s angle, but when I tried to alter the gradient itself (1s to 2s), Synfig acts as though it is tweening between two static images rather than moving the colour stops to create a smooth sweeping effect.

As the animation has a fairly tight schedule, I may have to abandon that idea for something else…
animate conic texture.sifz (720 Bytes)

Interpolating gradients is kinda tricky. Program never knows if you want to fuse the color stops or move them.
Try to convert the gradient parameter into a Gradient Rotate type. Then animate the amount of rotation for the gradient (to control the aperture) and the angle of the layer (to control the global rotation).
gradient-rotate.sifz (826 Bytes)

It shouldn’t be this hard to do something so simple. :laughing:
pacman.sifz (2.07 KB)

I can open Genete’s file but not Yoyobuae’s in 0.64.0.

In any case, circle sector is a shape common enough to become part of the circle tool IMO. Inkscape has incorporated that pretty nicely.

Take #2.

Seems the above file got corrupted just before I uploaded it. :confused:

Had to manually fix the order of exported valuenodes in XML file to fix it.

Added two files, one without using Straight Onto blend method which shows the inner workings. And the one with Straight Onto blend method which shows the working animation.
pacman-2.sif (20.4 KB)
pacman-1.sif (20.8 KB)