GF5: Animating 3D Characters

Motivation

Animated characters look magical, but the core ideas are concrete:

• a surface that looks like a person or creature
• an internal skeleton that gives it structure
• motion data that says how the body changes over time
• rendering choices that make the result readable

The project studies those pieces directly, starting with a block character where the hierarchy is visible before moving toward human-avatar scenes.

Immersive Virtual Characters

AI Rigging & Neural Layer

What This Project Is About

Build a small character-animation pipeline, then use it to create an animated human-avatar scene.

This project studies a simple version of the character-animation pipeline:

1. represent a character as a skeleton and a mesh
2. pose the skeleton with forward kinematics
3. attach a surface to that skeleton with skinning weights
4. turn a sequence of poses into a short animation

The emphasis is on understanding the mechanics of animation, not on learning a large authoring package.

Four-Week Shape

Assessment

Calendar

For the BE454 help sessions, a booking system will be set up later so that too many people do not arrive at the same time. You can still drop by the office.

Intro Slides

Open the hosted intro slides for the first session. The Notes panel works on the hosted page; notes are cached in the browser on that device.

To keep your own notes as a Markdown file in the project folder, run this from the repository root:

python3 slides/serve.py

Then open http://127.0.0.1:8095/intro.html. Your notes are saved to slides/student_notes/intro_notes.md.

To rebuild the same HTML locally, run python3 docs/build_site.py and then python3 slides/build_slides.py.

Assumed Background

You are expected to be comfortable with:

• basic Python
• vectors and matrices
• reading and modifying small codebases

You are not expected to have prior experience with:

• 3D graphics
• rigging
• animation software
• SMPL or human-body models

Before running the viewer, create the Python environment from the shipped env.yml file.

Why The Project Starts With A Block Character

The early parts use a blocky articulated character rather than a realistic human mesh.

That is deliberate. A block character makes the hierarchy easy to see:

• each body part is rigid
• each joint is easy to identify
• FK bugs are visually obvious

Once the skeleton logic is clear, we switch to SMPL and study mesh deformation.

Project Parts

Part 1

Focus:

• joint hierarchies
• local versus world transforms
• forward kinematics
• key poses and timeline-based motion authoring

See Part 1 for the exact coding tasks, required outputs, and the part-1 material that must be prepared for the interim report.

Part 2

Focus:

• rest pose
• skinning weights
• one-hot skinning
• comparison with linear blend skinning (LBS)
• motion reuse on SMPL

See Part 2 for the exact coding tasks and implementation requirements.

Part 3

Focus:

• later group character-animation work building on the same FK and skinning pipeline
• final brief and deliverables to be released after the interim checkpoint

The Part 3 brief is not part of the current Parts 1 and 2 release. Use the Part 3 placeholder for release status.

Interim Checkpoint

At the end of Part 2, you should have enough material for an interim report.

The exact required content, figures, videos, code submission, and report structure are defined in the relevant handouts:

• Part 1 for the part-1 material you must carry forward
• Part 2 for the skinning tasks and evidence you need to collect
• Interim Report for the complete report and submission requirements

Use Of AI Tools

For Parts 1 and 2, do not use AI tools to generate your submitted code, derive the core math for you, or generate your results.

For Parts 3 and 4, you may use AI tools as part of the creative or production workflow. The focus is still to create a realistic, controllable 3D avatar rendering scene and to explain how your group produced it.

For both reports, do not use AI tools to generate the report content wholesale. Minor grammar, wording, or formatting help is allowed, but the explanation, figures, results, and interpretation must be yours.

Every report must include an AI Use Statement saying either No AI tools used, or describing the limited use you made of AI tools.

Main Files

The core teaching code lives in:

• viewer/asset_viewer.py
• viewer/motion_sequences.py
• viewer/skeleton_profiles.py
• viewer/smpl_support.py

The viewer is used throughout Parts 1 and 2 for:

• skeleton inspection
• pose editing
• timeline authoring
• skinning-weight visualisation
• video export

It also provides the starting point for Part 3 motion preview and evidence export where appropriate after the later brief is released.