Need a quick bit of help with Bone Animation

As in the gif below, I want to make it so when I “move” the bones, the bone connected to it moves with it, instead of just rotating the selected bone. I know I can scale the connected bone, but I figured this way would be way more conveniant in the long run. If anyone has some tips on how this would work that would be great! I’m guessing I’d probably have to use some kind of controller (similar to using external clavical controlls, for example) But I don’t know where to start.

Thanks in advance!


You mention two things here: moving and scaling. If I understand correctly, you need to use Inverse Kinematics to have the parent bones move with a child bone. You can set up a constraint manually, or try the Auto IK (checkbox under Tool in the N-panel) for this simple rig.

To have other bones scale when you scale the top bone, perhaps try a copy scale constraint.

I guess I should be more specific,
There’s the box, the rectangle in between and the triangle;
What I want to happen, is to be able to move the triangle freely, wihtout it affecting the box but still deforming the rectangle. Currently all I can do is rotate, but I want to me able to rotate, move and scale independantly. Does that make sense? I’m sorry, I’m still fairly new to blender.

I admit I do not see what the big picture is of what you are trying to accomplish. But, how about this -
TriangleRectangleBox.blend (909.6 KB)

The idea is that it’s supposed to be a “WhipSword” In which the squares and triangle make up the sword and when swung extend out like a whip.

Like Ivy’s whip sword from the soul caliber series

That helps. Not familiar with the series, but plenty of images and videos on internet. Next questions: Are you looking to pose the sword for stills, or use it in animations? For a more realistic look, or low-poly for game use? The reason I ask is that for the game, for instance, the sword moves so fast that it is really a line with some particle effects spaced out along it. Also, for a still image, a simpler armature would work since you would not need to animate it, or have it detect if it hit something.

It’s really just for animation practice/still learning how blender works. I admit it seems I’ve bitten off more than I can chew here aha, but it would be neet to figure it out. I’ve recently come across from 3ds max as the student liscence I had to that expired and I’ve not got the money to pay for it. I’m comfortable enough with the actual animating part, it’s just blender itself that has me in a pickle.

And specifically for low poly models that are probably not even going to be shown to anyone.

Fair enough. As for the difficulty - you have to start somewhere. A few months from now, this will probably seem easy :slight_smile: What I am thinking of is a single cylinder parented (by weight) to 8 or so bones, with the “barbs” as individual objects parented directly to individual bones. Stlll trying to figure out how to grab the last bone and stretch all of them out evenly, though. I like responding to support questions as much to help out as to learn new things myself.

Getting them to stretch evenly just by pulling the end bit isn’t nessesary, I’m more than willing to do it manually bone by bone. I prefer that level of control anyway. It’s just geting the stretch of each individual link. Would it be possible to position constraint the bone to a seperate controller? like how it’s done in 3DS max? I’ve given it a basic try but I couldn’t get it to work.

You can add a Stretch To constraint to each bone targeting the bone above it. The file I uploaded has one of these. You will need to up-parent the bones, and add the constraint in Pose mode. In testing it, you need to work from the top down to pose: move top bone, then select top 2 bones and move them, then top three, etc.

So I figured it out!
I deleted the armature I had and started again, but this time, instead of creating a bone for each individual link and blade, I duplicated the original bone during edit mode and positioned them with just the blades, leaving the spaces in between empty. That way they have no parents and are therefore are not constrained by the bone below’s rotation. It’s a simple fix, and a flawed one at that, but what matters is that it works! lol. I would love to know if there is a way to actually set up a proper rig with controllers and everything. I’ll play around with it some more and see what I come up with.

I’ll post a gif of what I mean in a sec

I’m playing around with some constraints now to see if I can get it to stop no closer than a set distance from the closest bone, so they don’t clip into each other

This is similar to what I was doing - the Stretch To constraint would allow the shaft to be parented to the armature and be deformed by the bones. I am not familiar with 3DS, but found this on the Autodesk site:
“Technically, there is no difference between a controller and a constraint. A constraint is simply a controller that requires the use of a second object.”

I would think there is a way to emulate 3DS “controllers,” but am not sure. The animation system in Blender is due for an upgrade this year (it’s part of a long list of things :frowning:). There are add-ons (like Animation Nodes) which may cover this. I’ve got a couple ideas, but it’s late, and I 'll have to look at it again tomorrow.

By controller, I mean more of a seperate object (In most cases a simple bezier circle that goes around the limb it’s controlling) that then has a constraint applied from the bone to it that you use to control the bone, instead of controlling the bone directly. The benefit of this being that you can set it up to control things like IK-FK Kinematic balance, angle the knee when there is IK applied from the foot to the pelvis, etc etc.

Just so you know, you can do this with parented bones as well. In edit mode, alt -p -> disconnect bone. This will make it so the bone can move around.

“Connected” is the trait that’s sticking the bone to its parent. You can also set this (probably only in edit mode) on properties/bone/relations IIRC. When you extrude a bone, it defaults to connected, but subdivison, duplication, etc, just inherits that property from the target of the operation.

As far as I can tell, connected doesn’t really mean anything, besides creating movement transform locks. But I dunno, maybe there’s something subtle that I never noticed.

Hey, This is achievable several different ways, as Phil_n said you could use a ‘stretch to’ const with bones parented to the stretch bone (make sure they DO NOT inherent scale), you can create a chain of bones (like in your Gif) using a ‘limit distance’ const either targeting the previous bone or the handle bone or even the tip bone, you could use an IK - but that would be similar to using the ‘stretch to’ const. These are just a few off the top of my head, there are prob more ways.