What Are Splines? What’s the Best Way to Approach Editing Splines When Animating?

Before I go into this topic, I wanted to mention that I think Victor Navone provides some really good tips and tricks on his website
(http://www.navone.org/HTML/Tutorials.htm) for splining.

So go check it out! I’d listen to that before any of my nonsense.

So…if your still here, here’s my 2 cents!

I find that this is a particularly difficult topic to talk about. Mainly because everyone I know does it a different way. Some animators never look at their splines, some use lots of keys on their splines, and some use only a few keys and rely on weighted tangents. There is no right and wrong way. Teachers may try and tell you there is, but that’s only because they see it works for them and they might think everyone will enjoy the same success. Unfortunately, I’ve learned it doesn’t work that way. All that matters is what’s on screen, not how it looks in your graph editor. So be sure you find a way that works for you and use it, even if it makes no sense to anyone else.

When it comes to my workflow, I don’t look at my graph editor until my blocking is pretty much complete. I make sure that all the acting and action that is supposed to take place in my shot happens in blocking. I am personally unable to define actions through splining. So when I take my shot from blocking to spline, that is the first time I take a look at the spaghetti mess in my graph editor. Luckily, since I’ve already laid down a lot of keys in my blocking (key pose, breakdowns, ease in’s and outs, overshoots, settles), I can roughly see an overall direction that my splines are traveling in. For some splines, all I have to do is clean them up so that they flow nicely. But most require a lot of attention.

The thing that really helped me to understand my splines is thinking of them like a roller coaster ride and the spline is the track the cars follow on. It can be fast, slow, it can have a big building anticipation followed by a quick action, take sharp turns and stop abruptly. The track is mainly a smooth track and even the sharpest of corners are rounded. Rarely are there any arbitrary sharp angles or jittery textures. It’s because the cars have weight. If halfway through the ride the track hit a 90 degree turn, it would be like hitting a wall, and it would remove all feeling of weight. So would your animation. Weight effects everything, including how your curves start and stop. It takes some effort to get the cars moving and even more to get them to stop. Remember how it feels going up the incline and then having gravity catch up to you on the fall, and then remember what that track looks like. Your spline for that may look the same in Trans Y.

Some tidbits I’ve learned along the way:

I almost only use SPLINE tangents. Always making sure that the splines flow through and to eachother. Never overshooting, undercutting or slamming into each other.

Always zoom in close to see how they really look. Some curves look clean until you zoom in.

The heavier the object the smoother the splines may be.

Most actions can be represented by an “s” curving spline. Starts flat, has a little dip (antic) moves up a slope (action), overshoots, and settles down to its next resting place.

I rarely use linear knots.

I feather into almost everything. Even some of the sharpest hits have a little padding.

Most of the curves can remain pretty clean.

Rarely do things start and stop on the same frame. Break up body parts as well as rotational and translation values on everything.

If my curves for TransY and TransX interweave like a DNA helix I will get a circular pattern.

Guest Blogger Nick Bruno