100% REAL walking mechanism!

(Cognis) #1

I finally got the hang of hinges (no pun). I tested my knowledge and ended up with an actual walking leg mechanism that WALKS. No fake walk cycles, no bone action sequences, it WALKS, putting a foot on the ground, shifting its weight to it, and pushing off on it. Real, life-simulating walking, 100%.


I have some minor issues that need fixing, and I need some guidance.

1: The hinges are ‘springy’. When the legs move, the figure wobbles slightly; the quicker movement, the more wobble. Any way to turn that off?

2: Traction is poor. I tried pumping Gravity to its maximum 25, and it helped slightly. Coloumb friction (in Material DYN) is at max already, and I tried the same with
the plane it walks on. It still ‘slips’.

If those two problems can be solved, we have a fully functional core walker for the GE :smiley:

(well, I do, anyway, and will post it for free use. If others like it… yay!)

EDIT: Oh yeah, you move the legs with the up and down arrows, and shift weight left-right with the left and right arrows!


(OTO) #2

what are we supposed to do, to make the “thing” move? Shake the screen?! :slight_smile:
I’ve opened the file, pressed P and the object don’t move?!
Using the arrow keys, the “thing” becomes funny!!


(Cognis) #3

If you press left or right arrow key, the ‘thing’ tilts to either side, putting its weight on that leg. If you press up or down arrow, it moves its legs (bend or stretch). Put weight on one foot, move legs, then shift weight to other foot, move legs again. If you shake the screen hard enough, the walker will become a beautiful butterfly and devour your keyboard :stuck_out_tongue:

We are talking basic, manual control of legs, not just “point me in a direction and I walk”. That can be made, but it is not the vital focus right now.

Also, I think I solved the traction problem. I still need to learn something to kill that springiness in the hinges, tho…

EDIT: I did a record of the walker walking, you can get an idea from that:
http://www.crispquality.com/3D/WalkerAnim.blend - just run the animation!


(Canadian Hoser) #4

Your springyness may be caused by a scaled object. try ctr-a on everything or try building it again and scaling your objects inedit mode


(OTO) #5

Ah, ok, thank you!


(Cognis) #6

@Canadian Hoser: Thanks. Tried that now. No luck. This is really bugging me :frowning:


(Olm-Z) #7

This is interresting. I think the general idea is not bad, but needs more work. (it should deport it’s weight by itself f.ex.)
concerning a 4 (or more) legged system, I have a suggestion for you : strandbeest.com by Theo Jansens
look at this artist work and try to implement his walk cycle, It is realy simple and effective. I also realy find the work amazing, as it goes far beyond the walk cycle and he build real “wind robots” that move and react to their environment only with mechanical and fluid systems… (damn, neederland’s people can be realy good sometimes!)
Some people already did replicate the walk cycle on other software, but always as a “gimick” and never as a realy functional and reusable setup. If you have some time (which I have not for now) you could implement it. It could be realy usefull for games using animals like for ex. horses, dogs, insects, etc…


(patricia3d) #8

I have downloaded both blend file, and not able to understand how a character will walk?
Please give some help…



(wartree) #9

this could be good with some more work


(Cognis) #10

Yes, the walker needs more work. A lot more, to fit MY needs (machinima!). I posted this early version for two reasons: To spark some ideas/interest/debate on the concept, and to get someone to help me solve the one last remaining problem: How do I kill the hinge elasticity so the darn thing stops wobbling?

Once that is solved, I will began work on a complete biped walking system, from hip to toe, with near-complete realism, turning, jumping, running, crouching, and more! (heck, if I can manage it, I’ll even teach it to dance). But that elasticity/wobbling has to be solved first. Please someone help me! :eek: (Obi-wan Kenobi, you are my only hope)

It is very manual: Use left and right arrow key to shift the walker’s weight from one foot to the other. Once it leans enough to put one foot in the air, use up and down arrow keys to bend and stretch the legs. Once bent, shift weight to other foot and repeat.

You can do some freaky moves (and funny walks!) once you get the hang of it, but it takes a little while to get a good overview of the manual style. If the wobbling gets fixed, you’ll see much easier systems!


(Mico27) #11

to decrease the “spring” effect increase the size of the bounds of the object (in logic tabs, its actually called “form”)


(Cognis) #12

I can find neither “bound size” nor “form” anywhere. I can only find Radius, located under the Rigid Body tab. Do you have a screenshot?


(Ace Dragon) #13

I think radius is bound size, and I think Erwin got rid of form as I don’t think it’s really needed anymore.


(Cognis) #14


What really bugs me is that I know it can be done. IanC got it right in his learning quadruped, but I cannot deduce what he did right, and he seems as baffled as me (in PM)…

Are there any really in-depth tuts on Rigid Body Joints around?


(Ace Dragon) #15

The truth is, the Bullet physics are quite a bit more stable then they used to be, so form to control jitteryness isn’t really needed anymore. If all else fails Erwin has his own forum where he answers questions related to Bullet physics and Blender.


(Cognis) #16

I think I got it… seems rigid bodies respond quite differently to hinges than standard Dynamic Actors. I’ll be testing the theory this weekend!

PS: Got a link to Erwin’s forum? Might come in VERY handy soon :slight_smile:


(ChicOrtiz) #17

Erwin’s forum: http://www.bulletphysics.com/Bullet/phpBB3/

By the way awesome idea. I hate timelines : )).


(Túrin Turambar) #18

Cool stuff man!


(_LsBlend) #19

Erwin got rid of form as I don’t think it’s really needed anymore.

wait, form was still useful to me :frowning:


(Canadian Hoser) #20

Wow, why didn’t you use rigid bodies? thats your problem. the constraints have a different effect on them. Also, they have no rotational velocity, so when you do d-rot as rotation, it has no acceleration and that is what jerks the hinges around.