No Bones Suspension Animation with IK Handle and Target

[ZooHead]

I wanted to set up a system to test different suspension configurations after coming
across a worksheet made by Koni, a major shock absorber manufacturer.

I was fascinated by the suspension configuration on the worksheet,
and wondered what it would look like if I animated it.
I'm not a mechanic so I never realized the pivot points don't have
to make a parallelogram, so visualizing it in motion is not easy.

When animating any complex system, be it character or mechanical, you want to
set it up so you can animate one part that will drive other parts to simplify animation.

For organic bendy things, working with Bones is probably the best way,
but with rigid mechanical stuff using Joints/Bones/Skeleton is unnecessary.

I've used Bones for mech stuff before, because I
thought I had to in order to use the IK Handle Tag.

But the IK Handle works on Polygon Objects as well as Bones.

 

[Helmut]

Great stuff, ZooHead, and very informative.
* I need a conceptually similar dynamic for a 3D (not planar 2D) abstract animation and will experiment. Thank you for the idea! I have had, as yet, very limited expertise in inverse kinematics and associated trickery.

 

[ZooHead]

Thanks Helmut I'm glad it's helpful.

I will add a shock absorber and show a 3D
model based on the same pivot points.

 

[ZooHead]

For the animation setup it's the second object in the hierarchy you can animate.
Since I started with the frame and worked around clockwise the second object is
the bottom arm. But if I start with the ball joint object, the second object is
the Top Arm, it's pivot point is at the top ball.

Also you can swap all the objects pivot points
to the other end and see what that does.

The End At Frame object must be moved to the pivot point of
the first object of course. I should have named it End Of Linkage.

 

[ZooHead]

Here's a 3D version, with the same geometry.

 

[ZooHead]

It can be very helpful to make a pivot point guide from a spline or polygon.
That way snapping to pivot points will always be easy.

For my next version that will be the first thing I do.

 

[ZooHead]

Once I show how I add the shock components,
I want to try a long travel ATV suspension.

 

[ZooHead]

Since this is a mechanical linkage, I thought this would be interesting.
By Pasimi - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=67353419

 

[ZooHead]

I couldn't help myself, I had to try one.

All splines.

 

[ZooHead]

Here's an alternate setup with all things visible.

The blue line, called a Pole indicates which way the linkage points.
Without the Pole the linkage will flip back and forth.

The purple line shows the IK Handle connection.
Both the Pole and Target object are folders, but they can be any object.

This time instead of putting everything in a folder to be able to move the
whole assembly, I used the spline Arc Line, which is just a graphic indicator.

Also I'm using the Orthographic Camera to remove perspective.

 

[ZooHead]

I copied the link system, removed the keyframes from the
copy and added a Orient Constraint Tag to the drive arm.

The target of the OC Tag is the original Drive Arm,
so it's still the only thing keyframed.

Then I moved the IK Target to move the pivot point further away.
All other things remain the same.

Notice the difference in the acceleration curve.

 

[ZooHead]

Here's one to experiment with.
Tip: Top Down View and Priority change.

I wonder if it can be driven by the slider?

 

[Chris Heath]

Here's one to experiment with.
Tip: Top Down View and Priority change.

I wonder if it can be driven by the slider?

It reminds me of a piston. So if you put the slider in a cylinder and add a spark plug, injector and some petrol, then yes. BTW, I’m no engineer, so knowledge of mechanics and what is under the bonnet of my car is limited.

 

[frank beckmann]

I wonder if it can be driven by the slider?

I doubt that because once splines are aligned to 180° it´ll most likely stop as there´s no "real" force or dynamic to push it any further in a "directed" direction. If this sentence makes sense.

 

[ZooHead]

I doubt that because once splines are aligned to 180° it´ll most likely stop as there´s no "real" force or dynamic to push it any further in a "directed" direction. If this sentence makes sense.

I suspected as much. There's no flywheel action, no inertia.

If this system mimics a steam train drive system, I wonder what
happens to a train if it stops at a point where everything is aligned.

 

[ZooHead]

Here's a version of a piston drive system I've started playing with.

Can you tell what it's going to be?

 

[ZooHead]

The previous animation was my first iteration of an illustration of a 9 cylinder radial engine.

The design was surprising to me because the top piston
rod is one piece and the other eight are articulating.

This top piston rod is called the Master Rod.