Sketching on a BLine

I’m wondering if it is possible to create a permanent sketch on a BLine and leave it there. For instance, I want to create a hand with fingers. The hand and fingers will be a BLine region. Nodes in the BLine region will allow me to move the fingers and animate them. However, I want to make the hand detailed, so I want to add fingernails. I don’t want to animate or move the fingernails. I just want the fingernails to be part of the BLine, like a painting or a sketch (or even a tatoo) on the BLine that stays there on the BLine while the BLine moves and animates.

In my attempts so far, my sketch remains part of the background while my BLine hand moves away from the fingernails. The fingernails will not move with the finger. How can I attach images, like fingernails, to the fingers (BLine) so that they will move along with the fingers?

In other words, how can I sketch on my Blines? Thanks.

What you want is to have a bone system that is not implemented yet. Moving the bone it drags all the details around the bone.

In the current state of art you can do some tricks to “carry” details from other layers based on the parameters of one layer.

Say you have an arm that is made by a Region layer. Then the arm has a tattoo (it can be a entire composition just grouped into a Group layer). Maybe the tattoo is placed in the middle point of the two vertexes of the arm joint and aligned with the top and middle vertexes of the arm.

So then, you can do math calculations on how the tattoo should be placed based on the location of the rest of elements. With that information you could convert the position and the rotation of the tattoo to make it dependent of the values of the parameters of the arm.

The hand of the character of the unfinished contest entry is made based on this idea:

Good luck!

Oh wow. That sounds more complicated than I had hoped. I just want to put pupils in the eyes and strands of hair on the head of a character that I’ve made in Synfig. I don’t want to pupils to be BLines or SLines, i want them to be permanent marks on the eyes. Marks that don’t leave and stay on the eye when I’m animating the character. Not possible?

So you need to group the pupil together with the eye components and animate it as a whole using the Group Layer (old named Paste Canvas Layer)

Got it. I figured it out. Then I can make them a single piece (sort of) through encapsulation. Before I was thinking that there might be a way to sort of tattoo the regions just to simplify things. Hair is going to be a challenge if you want detail, right? Sketching in hair frame by frame might create an interesting effect. Lots of work though hehe. I’m working on my first two large projects on Synfig (they’re both only about 4min cartoons but to me, they are huge). Sometimes i really need to concentrate on the physics of it…where each vertex is, and where they are moving. In the animation world, I’ll bet there’s a term to describe those mistakes when lines overlap on accident…