LearnViz CompSci
Home / Learn / Graphics, Vision & Media / Skeletal Animation

Intermediate Topic 29 of 49 Graphics, Vision & Media

Skeletal Animation

Moving a mesh by deforming an underlying skeleton.

How it works

Skeletal animation deforms a mesh using a hierarchy of bones, a skeleton. Each vertex stores weights linking it to a few bones, and in linear blend skinning, its final position is the weighted sum of the positions it would have under each bone's transformation relative to the bind pose. Animators or motion capture provide keyframes for bone rotations, which are interpolated, with quaternions, and blended between clips. Inverse kinematics lets a chain reach targets, such as a foot on the ground, and blend trees or state machines drive characters.

Where it is used

Characters and creatures in games and films, avatars in virtual reality and motion-capture-driven performances use skeletal animation.

Common pitfall

Linear blend skinning causes volume loss and candy-wrapper twisting at joints, so use dual quaternions, corrective blend shapes or more bones. Wrong bone weights stretch geometry. Hierarchy and bind pose mismatches break retargeting between characters. Limit the number of influences per vertex for performance, and test extreme poses.

Where it fits in the course

Skeletal Animation is topic 29 of 49 in Graphics, Vision & Media, rated Intermediate. It follows Mesh Simplification. The next topic is Physics Engines.

Practice and explore

How to study this topic

  1. Read the explanation above and restate the definition in your own words.
  2. Open the interactive lesson and answer its mini quiz.
  3. Read the common pitfall, then write a short example that avoids it.
  4. Check your understanding in the Graphics, Vision & Media quiz, and revisit the topic if you miss a question.

Frequently asked questions

What is Skeletal Animation?
Moving a mesh by deforming an underlying skeleton. It belongs to Graphics, Vision & Media and is an intermediate-level topic.
Where do people use Skeletal Animation?
Characters and creatures in games and films, avatars in virtual reality and motion-capture-driven performances use skeletal animation.
What is the most common mistake with Skeletal Animation?
Linear blend skinning causes volume loss and candy-wrapper twisting at joints, so use dual quaternions, corrective blend shapes or more bones.
What should I learn before this topic?
Start with Mesh Simplification, the topic just before it in Graphics, Vision & Media.
How can I practice it?
Answer the mini quiz in the interactive lesson, then take the Graphics, Vision & Media quiz.
Is Skeletal Animation hard to learn?
It is an Intermediate topic. Be comfortable with the Beginner topics in this area first, then read the common pitfall carefully, since it is where most mistakes happen.
How long does it take to learn Skeletal Animation?
Most learners can read the explanation and finish the interactive lesson in under an hour. Fluency comes from applying the idea, so plan a few short practice sessions with the quiz.
Which topics are related to Skeletal Animation?
Mesh Simplification, Physics Engines, Bézier Curves and Splines are closely connected. The full list is in the related topics section of this page.
What should I study after Skeletal Animation?
Continue with Physics Engines, the next topic in Graphics, Vision & Media.

Related topics