Driven physics

Hi!

So I finally got around to testing rig-driven physical actuators, and it turns out, they work just fine.
Video here:

Obviously it’s not well animated, but this was just a quick test. I can’t upload the blend of that animation, because it’s too big even without being baked. I will upload another blend though.

[ATTACH=CONFIG]482575[/ATTACH]

You’ll see a leg similar to the ones in the animation, it can be controlled from the spherical empty. Now, the foot part is wrong - I made it without planning for dampeners and springs, so don’t pay much attention to it.

There are also 4 pistons near the center of the world. The one closest to the center is the linear actuator, followed by the compression spring/dampener made of linear motors, followed by the compression spring/dampener made with the bullet spring joint(which is just too bouncy for most situations), and finally just the dampener.

The settings for the pistons are in the top cube empty’s. The linear actuator is controlled by the distance between its empty’s. In the case of the other 3 pistons, the positions of the empty’s play no role in their simulation.

The next step is to make and animate a more proper walker, possibly a biped. I hope you find some use for this stuff as well, and make some awesome animations.

Hi maqster,

this looks cool, but I am not sure which part is animated and which part is dynamic. The pistons are dynamic ? Could you elaborate ? (also your attachment is dead) I am very curious to dive into that blend file.

Hadrien

Sorry about the attachment, I guess blenderartists doesn’t keep it for long. Google drive version here: https://drive.google.com/open?id=0B-MK_zPbMSFGLWR6czM3bHJveDg

Might as well share the original now: https://drive.google.com/open?id=0B-MK_zPbMSFGMnhHeTRoYzQ2ZWs
Although by now I have removed the cubes and the bake from the original file.

It should become more clear when you open one of the blends, but I’ll elaborate anywway. The linear actuators’s speed is controlled by the difference between the distance between the controllers (the emptys) and the distance between the ends of the actual physical pistons. The upper empty of the linear actuator in temp68.blend contains the settings of the linear actuator. You should place it on your rig with the emptys. The emptys should be parented to the rig (probably armature bones). Then the actuator armatures should be disconnected from the emptys and placed on your identically jointed(as your armature or whatever control structure) physical rig (composed of rigid bodies and joints). There is one joint (a 90dec curved double ended arrow looking object) on either end of the linear actuator, that is only physically connected to one object. These should also be connected to your physical leg or whatever moving parts. Then you should make a random part active, grab it with g, and release it without moving it to update the drivers (Blender doesn’t seem to always update drivers, so this should be done). After that you should activate the control empty of the actuator (the thicker end one) and go to the object tab. There you will see the custom properties. The length_current value needs to be made the same as length_initial property (note, that you cannot copy it, since length_current is driven). Then length_max and legth_min should be set according to your situation (length_initial, length_max and length_min are neccessary to set up the limits of the actuator). The rest should be pretty obvious, but feel free to ask anything.

Ok I fiddled a bit with it. Very interesting. To be honest, I had no idea this was possible - I never played with the rigid body constraints before, but this… is so cool. I changed the animation a bit and the beast immediately toppled. If you don’t want it to fall you have to be SUPER careful to animate the legs in sync… wow !

Any luck with the biped version ?
By the way you should see this : https://vimeo.com/79098420

So, it’s been a while.

Didn’t get to the biped one, but here’s a truck-thingy: https://youtu.be/JjXvi9d28zE
It has constant power and steering in the video, but of course it can driven manually. It’s pretty fun.

What i might try next is some spaceship stuff, maybe even try some docking couplers. Or some VTOL aircraft like a carryall maybe.

That Vimeo link is interesting, i may have seen it before.
I don’t want to get that fancy tho. I’m just interested in making various machines and playing around with them. Could also be useful for actual animations.

That’s a pretty cool video. I’m not going for anything that fancy.

So it’s been a while and no biped. But I made this truck-thing: https://www.youtube.com/watch?v=JjXvi9d28zE
It drives pretty well. If someone wants the blend, I can upload it to drive.

Next I might do some spaceship or VTOL stuff.