
Overview of Inverse Kinematics - dmit
https://medium.com/unity3danimation/overview-of-inverse-kinematics-9769a43ba956
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dyarosla
I mean.. it describes that Inverse Kinematics _is_ and _is used for_ , but
literally none of the math that makes it work. More than a little
disappointed.

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beluis3d
Hey, thanks for reading. There are a TON of ways to implement Inverse
Kinematics, and I'm going to cover the most popular ones in coming articles.
Do you have any preferred animation techniques you'd like me to cover? All of
my articles will be available here:
[https://medium.com/unity3danimation](https://medium.com/unity3danimation)

~~~
cbames89
I'll make a plug for software I wrote based on sequential quadratic
programming. It performs significantly better than inverse Jacobian methods in
the presence of high-dof and joint limits. Here's a link to the software and
paper:
[https://bitbucket.org/traclabs/trac_ik](https://bitbucket.org/traclabs/trac_ik)

~~~
bhouston
Very interesting.

What is the best IK algorithm to implement in JavaScript given that it has to
be small enough to download but also robust and fast and probably something
one can implement without spending too much time on it? Probably an impossible
question... but I figured I'd ask in the hopes there was something easy and
obvious here.

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beluis3d
FABRIK: [https://medium.com/unity3danimation/create-your-own-ik-in-
un...](https://medium.com/unity3danimation/create-your-own-ik-in-
unity3d-989debd86770)

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Isamu
This is a good intuitive explanation of IK meant for someone who is doing 3d
animation or modeling. Maybe not for somebody who would be actually developing
kinematics, for whom an overview of the matrix math is needed.

Given that, I still cannot understand WHY they use these user-unfriendly terms
in animation and 3d modeling.

Yeah, I developed inverse kinematics and coded them up. But even then we spoke
in terms of world coordinates vs. joint coordinates.

Joint coordinates -> you are specifying joint angles -> forward kinematics

World coordinates -> you are specifying a point in world space -> inverse
kinematics

Really it is unhelpful to use the terms IK/FK with end users like animators
and artists.

~~~
gmiller123456
>But even then we spoke in terms of world coordinates vs. joint coordinates.

World vs. joint coordinates might also generate some confusion, since joint
coordinates are "world" coordinates too. And you can refer to the coordinates
of a joint using "world" coordinates, which someone could easily refer to as a
"joint coordinate". Of course, you can formally define exactly what these
terms mean, but then you've lost all of the advantage of using common terms
rather than more formal terms since you've replaced the common meaning of
those terms with a formal one.

