Best way to controll an excavator arm?

W35137 · August 2, 2016, 9:13pm

So, in my project I’m trying to create a fully controllable excavator (one of those big construction tractors you often see at dig sites with the pneumatic arms.) I’ve already got the treads and cabin rotation controllable, but the arm is stumping me a bit. It currently has 6 animations; two for each of the three joints moving up or down. Playing the animation to rotate part of the arm (the boom for instance), is all well and good until I then try to rotate a different part (the bucket). Being animations, this naturally causes the first change I made to the arm to reset to the starting position so the new animation can play. I’m not even sure blending is what I want, since ideally each joint on the arm would be completely independent from the other joints. Animations were initially used in order to keep the pistons and pneumatic hoses behaving properly as the arm bent, but that may not be worth it if that’s just not a good way to control it…I’m pretty new to Unreal, so I’m not sure on the ideal path to take for this.

Just wondering if anyone had a recommendation on what method to use for something like this.

DennyR · August 2, 2016, 9:47pm

I think you are looking for SkeletalControls inside of an AnimBlueprint. These allow you to control each bone individually and then blend them together as a final pose.
You can drive each of the rotations from a blueprint or control inputs.

Erasio · August 2, 2016, 9:53pm

I would honestly recommend using a very simple skeleton and drive it via animations.

Via Additive Animations you can quite easily move each piston controlled part independently with an easy enough setup.

Cheers

Edit: Oh. Listen to DennyR. His solution is much better!

W35137 · August 8, 2016, 2:21pm

Ahh, yeah that did the trick. Had to pass some variables down the line to be able to use them in the animation blueprint, but they work nicely once there. The pneumatic pistons aren’t animating with the rest of the arm any more, (they were bones using the look-at function when they were imported-skeletal controls probably don’t support this) but that’s a different issue. Thanks!