Hey. Welcome back to the development diary. This will be the third and probably final entry about Machiko's visual design, and I'll be writing specifically about her facial expressions. That might seem like a limited topic at first but it was an aspect of her design that needed a lot of care and attention.
For a start, in Nekodeito the player will spend a lot of their time looking at Machiko. She's the sole love interest of the game, and so it would become a bit stale after a few hours if the character sprite wasn't very active. A visual novel is a hybrid medium that relies upon on-screen stimulation to augment what the player reads in the message box and hears through their speakers. Access to a wide range of facial expression lets us change that expression often, making the experience feel a lot closer to having a real face-to-face conversation. It's worth remembering too, much of our communication as humans is nonverbal. Our expression and our body language factor into our meaning when we talk as much as the words we actually speak.
So with that in mind, suppose we say to ourselves, "okay, four expressions should cover the range of emotion our character will have in the game." And we go to our artist and order those four expressions. Kind of like this:
Great. We have four sprites. But we're still a bit limited in what we can do. We won't realistically go through these specific these emotions in every scene, unless it's a real emotional rollercoaster. If we consider however what is the same and what is different in these four examples. The shape of her head and the general position of all her features don't change a lot, yet each individual part of the face changes, and distinctly at that. We have four sets of eyes here, four mouths, three kinds of eyebrows and two kinds of ears. Multiply those together and we could get 96 possible combinations of features. If I ask an artist to draw me 96 sprites they will probably tell me to go away.
Instead, Machiko's sprite artist chlorophill created an extensive kit of face parts that can be combined together, complete with colour correction layers to account for their different shapes and ensure smooth blending with a miniscule amount of photoshop needed. We can do a lot more than 96 unique sprites with this. We can create hundreds of expressions before we even get into outfit and pose changes.
The flexibility of this method of compositing sprites really shines when it lets us just make subtle changes in expression. Below, between the first and second, all that changes are the eyes. Then between the second and third, we just change the eyebrows and the mouth. Just these three small changes do a great job of demonstrating an emotional progression from one feeling to the next. It's easy to see how a chains of small (and large!) changes in expression can really convey feeling in a scene.
Drawbacks of the system? Well, hundreds of combinations doesn't mean hundreds of good combinations. A lot will look quite silly, but I've been surprised so far just how wide a range of emotion can be conveyed with a well selected kit of parts. Hundreds of combinations also means there's a lot of sprites to be exported from photoshop, multiplied by her outfits and pose modifiers. I don't mind this exactly, and coming updates to our game engine lets us save a lot of duplicates we used to need and thus a lot of file space but it still remains a lot of .png files to organise in the engine.
But we'll talk more about that in the weeks to come when I'll write some articles on programming. Nekodeito has detailed catgirl petting mechanics that deserve their own article, as do some other things like UI design, background art and text delivery. I'm enjoying writing these short articles just as a personal exercise to get my thoughts in order and reflect on progress so far. They're a bit messy, but I hope they're interesting for you too. See you next time.