Question about traditonal animation drawing

[kori]

I have a question that is easy for those of you who have done animation drawings, but not for me. I don’t see the answer in my animation books, so I’ll ask you.

If you are drawing a series of animation character movements, and if the character drawings do not perfectly match the previous drawings, does it cause the lines to crawl or wiggle during pencil testing?

For example, if you have a character standing at three-quarter angle, and you draw an animation of his arm moving from his side up to a position of pointing at something in the distance. The parts (lines) of this body that do not move have to be traced, but they can’t be traced exactly (traditional animation) because hand drawing is not exact. There will always be a little movement of the lines, from drawing to drawing. Does this cause any problems like wiggly lines, or crawling lines during pencil testing?

[Mikdog]

Sure thing. Any movement will cause wiggly lines. Be sure to trace from the first drawing for the parts that don't move, or don't animate the parts that don't move. If you trace drawing 2 from drawing 1, then trace drawing 3 from drawing 2, then trace drawing 4 from drawing 3, etc... and your pencil line moves a little bit each time, but the end of it your character or whatever it is has wiggled a fair bit from its original position. The problem becomes exponential. But, if you're always tracing from drawing 1, then the wiggly lines won't be so severe because you're still locked to tracing one reference point. If that makes sense. Hey, wiggly lines can add to the charm of something I think. In fact, AS has a feature that causes wiggly lines for you so that everything's not so perfect.

[slice11217]

Well it's not specified in the post, but I'm assuming that you don't want wiggly lines, right?

in that case I have one thing to say: LAYERS!

That's right, layers. For years animators would animate characters on multiple layers so that they could isolate areas that aren't supposed to move from areas that are. So in your example, if your character is just standing there and his arm is supposed to move upward, then the body of the character (opposite arm, legs, head, etc.) would be drawn on one layer minus the animated arm, and then the animated arm would be drawn on its own layer. -You could also put lip sync on yet another layer so that he could talk while animating!

Otherwise, yeah, just draw it all on one sheet of paper and trace the previous drawing and you can get the wiggly lines.

[human]

If you are drawing a series of animation character movements, and if the character drawings do not perfectly match the previous drawings, does it cause the lines to crawl or wiggle during pencil testing?

Yes, definitely! It's called "boiling." There is an Oh-It's-Cute-And-I'll-Just-Call-It-"Art" school (usually involving crummy New Yorker-style drawings) which glorifies this, but animation professionals have absolutely ZERO tolerance for it.

Now what to do about it. In traditional hand-drawn animation, the cure for it is to create the inbetween (I think this is also called "breakdown") positions NOT sequentially BUT RATHER by halfway drawings.

Your animation books are surely showing you this in their diagrams, but they are failing to explain it in words.

At the risk of oversimplifying, you begin hand-animating by taking any two positions and draw the halfway position.

Then in the two segments you've just created, you draw the halfway position in them, too.

Then, you repeat this loop until you have either 12 frames per second or 24 frames per second for your sequence.

Now, there is a complication to this simple picture of "halfway."

Physical objects (like arms and legs) need to accelerate from rest, and then they need to decelerate to their rest position again. In the dumb lingo of animation, this is called ease-in/ease-out, but Isaac Newton would call it acceleration.

What this means is that the inbetween positions will seldom be exactly halfway. They will be more or less than halfway depending upon the speed of the object at that moment.

Go back to the diagrams of the bouncing balls which are going to be prominent in your books. The reason they harp on this so much is because the variation in position doesn't just apply to a bouncing ball--it applies to everything.

Now finally, the reason that pro animators are using Anime Studio, Flash, and Toon Boom (or 3D software) is because the computer can calculate the inbetweens WITHOUT CAUSING BOILING.

There! Does that help?

Corrections to this explanation by someone who knows what they're talking about are welcomed!

PS A question on just this topic is the first question I ever asked on this forum.

[kori]

Thanks everyone for the help. I think I have it down now.