Recently, I made this post about invisible legs and how they can be manipulated to make creatures look like they're flying (or swimming).
With five strategically placed legs with three feet each, this specific creation animates as though it's flying above the ground and flapping its wings. It's pretty neat!
However, I've only ever seen these invisible legs used to make creatures float, and while I was working on another creature for an old request in my inbox, I wondered if invisible legs could also be used to manipulate the movement of regular legs.
Specifically, this creature I was working on is shaped a bit like a kangaroo. Kangaroos, of course, are known for hopping rather than walking--in fact, they can't walk, and are only able to move by hopping.
But, Spore isn't made for that kind of movement on two legs.
Looking back at the dragon, the two pairs of hind and wing legs are both synced up, and if you isolate that motion, it looks more like hopping. I figured that if I created a similar set up with invisible legs for this one, I could get the two hind legs to rise and fall in sync.
Success! It isn't perfect, but it gets the job done. Now, with the walk cycle sorted out, I can work on building the rest of the creature, adding more details and other parts. I decided I wasn't happy with the head, so I started playing around with that.
... Huh? I didn't touch the legs at all, and yet, the removal and addition of different parts has altered the walk cycle. Interesting! I decided to do some testing, hypothesizing that maybe it had to do with the number of parts--perhaps whether the number was even or odd affected it. I added another pair of horns, but the walk cycle didn't change. Out of curiosity, I added a third pair...
... and it's back to hopping! But, if you compare it to the original hop, it's different. The normal hind legs are now synced with the invisible middle legs. As a result, the overall motion is more extreme and exaggerated, and the tail now collides with the ground.
I added another pair of horns, and now it's back to walking, but it still has a slightly different gait than the other walk. The normal hind legs and invisible middle legs are less synced up. Each added part seemed to make a difference... so I added one more pair of horns.
And mysteriously, that addition made it return to the original desired hopping motion. Fascinating!
With the knowledge that adding and removing parts changes the walk cycle, I decided to strip the legs off, finalize the design and all the parts, and leave the invisible legs for last.
It got a bit complicated. In addition to the two normal legs, it has five invisible legs. The two rear pairs have two feet each, and the single front leg has three feet. It isn't quite perfect, but it suits this kangaroo-like creature much better than a regular two-legged walk.
Beyond the final result, I don't have a satisfying conclusion for this post. The inner workings of Spore are as intriguing as they are befuddling--why do non-limb parts have a bearing on how a creature walks? What is it in the game's guts that dictates this? Is it a bug, or a feature? I don't know!
