There are some quite impressively designed robots in the SimplePlanes community so I thought I'd put my ideas out there and see what comes of it. (sorry, I'm not a speech-writer :p)
Honestly, I've only tried a couple of walkers but the instructions I've read follow a similar path to each other: Move each leg 1 at a time and sorta waddle, or gimp it. I did see a small toy-robot that walked using a wheel and pistons, that one was cool! My entry into this realm is a quadruped walker, using 2 analog sticks to bend the legs realistically.
Here is my experience with walkers in Banjo-Kazooie: Nuts & Bolts for x360.
Balance
The main problem we face, is keeping the darn thing from falling over. In N&B however, there were two solutions. The Balloon always stayed upright, thus pulling the mech like holding a toddlers' hand. However, this made the mech lighter, removing traction. The second method, which I'd like to explore in SP, was a (glitched) propeller. When a prop is placed on top of a vehicle in N&B, the game treats it as a helicopter and keeps it upright. Even if there was no power to the prop, it placed the walker into the 'Helicopter' category and kept it standing.
What if the walker was kept upright by a weighted propeller, loosely jointed to the top, and always on? The weight below the prop would keep it facing north (in theory) and always pulling up on the walker. Writing this out now, I see it resembles more of the balloon method :/, oh well.
Movement
In N&B we didn't have any joints in multiplayer to prevent glitches and the like, but someone still figured it out. Legs were attached like chain; two loose hoops connected but not. So to move the feet, rocket engines were used. Unlike their near-instant thrust in N&B, SP engines take a bit to kick in. However, the small thrusters can be rotated within 3 directions using just 2 buttons or slider positions...
To move each foot, 2 engines were mounted. Forwards & down on one foot, and reverse & up on the other. To walk, you would press gas, lifting and pushing out one leg, and dropping & pulling back the other. Then you would press brake, performing this step in reverse for the other leg. Weight distribution was handled by the helicopter attribute, by simply moving the left stick around.
In SP, I think I can perform this with the thrusters, using Roll to both tilt the hips, and operate the legs. For starters though I suggest using Roll for just the hips, and Yaw to fiddle with the legs: Right for the effect of 'gas' and left for 'brake'. Of course we can't use actual gas and brake due to that cutting out the support propeller... or could we?
This is why I am posting my work. What do YOU think?
(everyone's welcome, just tagging a few) @Scifieart @laSoul @MrMecha
@AgDynamics http://www.mekanizmalar.com/theo_jansen.html
@AgDynamics Ohhh I saw that many years ago & never thought more of it. Found a video of how it would look using Legos, and I think I'll try it next :).
@AgDynamics
I made a school report on Theo Jansen once...
The biggest problem we face with walkers in SP is that our inputs are either temporary (returning to neutral when the key/joystick is released) or unidirectional like the force from a thruster. This means that a leg cannot be extended and 'locked' into position without the use of activation groups, making the act of walking a very difficult and complicated process.
A mechanical walking mechanism with a single rotational input is entirely possible. A Dutch artist named Theo jansen created the Jansen Linkage which he uses in his moving sculptures called "Strandbeests," With this mechanism, a theoretically unlimited number of legs can be actuated by a single driveshaft.
I've got a partially functional Jansen leg built as just a proof of concept, but getting the geometry correct is really hard in the editor and will definitely require more work and some XML editing before I can implement it in a functioning vehicle.