Rigging Shadows

There was a Reddit post a couple of days ago about how the new Spider-man cartoon doesn't have any shadows. It isn't true - but the shadows are only used occasionally, and there are times when characters are standing on the ground with a clear light source nearby and don't cast a shadow at all (nor are their features toned). Like so:

For anyone well versed in Harmony, the problem is pretty obvious - making shadows work in Harmony is really, really difficult. More difficult than it should be, for certain. 

For those not very well versed in Harmony, here's a bit of a behind-the-scenes look at what I do. 

This is Toon Boom Harmony. In it, I've created and rigged a little birb. He's got a few things that already make him look more three-dimensional  than our aforementioned Spidey - he's got a tone node that gives him a bit of shadow on his body and around his eye, and he's got a shadow behind him. That shadow is cheated in there. It's just a circle run through the tone filter. And this is why. 

This is the node (or network) view. Despite looking like some arcane bit of wizardry, this is actually a relatively simple rig.* This makes it so that I can move the legs and keep them together, or move the whole body by shifting the torso around. Each of the little rectangle bits is 'node.' Nodes can be drawings, composites (areas that combine multiple drawings into a single entity), effects, or pegs (nodes that let you change stuff about your drawings without effecting the actual drawings themselves, or that let you easily move multiple drawings at once). Nodes can be made to follow one another - that's what the lines are all about. They represent connections between the nodes that effect how the nodes behave. 

So how do shadows fit into all of this? 

Some of the nodes in Harmony are easier to understand than others. For instance, the Blur node - you stick it between a drawing and the composite, and it blurs the edges of the drawing. Easy peasy lemon squeezy. Shadows should be pretty much the same thing, right? 

Except: no. Making a shadow is sort of a complicated thing in a 2d program. In 3d, it's actually a lot easier because you have a ground plane to work with, you have a program that sets up a light point, and then everything just follows that light point. In 2d there is no ground plane. There is one plane, the screen plane, and every bit of seeming three-dimensionality is a trick of the eye. So making a shadow in 2d means inventing a drawing and then finding a way to make that drawing look like it's a shadow, and then finding a way to make that shadow lie on a non-existent floor in a convincing way. Simple, right? 

What this essentially means is that you're creating another drawing for every single drawing you already have, and then offsetting those drawings to look more-or-less like they're lying on the floor. It is a giant pain in the ass. It's also time consuming, which I think is probably where the studio decided they didn't need shadows for every damned scene - they could do just as well with shadows when they're absolutely needed, and leave them out the rest of the time. What confuses me, though, is that there are easier ways that they didn't bother to implement.

You can make a shape into a shadow. In the little birb above, his shadow is just a single drawing, a circle that has a Shadow node attached to it. It's simple, but it works. You can even animate that shape independent of the object casting the shadow, which is all sorts of neat if you want to have a shadow transform into a character or something. This and the tone effect node are both super simple to use, and I'm not sure why the guys at Disney have decided to eschew them. The art on this little bird is atrocious (I made the art and the rig in like, two hours...), but it looks like it exists in a space a lot more effectively than the Spider-man art above. 

Here he is chirping at you, just because I didn't want the rig to go to waste. 

*For the people who care about such things - There is a single curve deformer on the poof on the birb's head, and everything else is a super-basic puppet rig. I didn't even bother pegging most of it. There is a cutter around the torso to keep the eyes in place, and another for the pupils. Those have color overrides to make sure they don't bleed over the black outlines. There are a couple of composite tricks I play to get the tone stuff working properly, and I got super lazy about the beak (which should have had a separate tone filter so I could overlap the eyes properly without sacrificing the beak's tone. This is just for the sake of example, though, and definitely not my best rig.