Animating Childlike Drawings with 2.5D Character Rigs

2025-02-25

AI Summary

This work addresses the challenge of driving complex 3D skeletal motion—particularly out-of-plane rotation—from children’s hand-drawn 2D characters while preserving their original artistic style and identity. We propose the first style-aware, view-dependent 2.5D rigging framework tailored to children’s drawings, integrating geometric deformation modeling with view-adaptive texture sampling to enable lightweight, real-time retargeting from a single sketch to multi-view 2.5D animation. To support this, we introduce a novel semantic annotation protocol specifically designed for children’s drawing characteristics. Its usability, child-friendliness, and style fidelity are rigorously validated through a dual-user study. The system supports cross-environment deployment (2D/3D) and demonstrates strong generalization across diverse scenarios alongside real-time performance.

Technology Category

• Computer Vision: Biometrics, Face, Gesture & Pose
• Humans and AI: Game Design — Virtual Humans, NPCs and Autonomous Characters
• Cognitive Modeling & Cognitive Systems: Computational Creativity

Application Category

• User Modeling, Personalization and Recommendation: Fairness-aware retrieval and ranking
• Search and Retrieval-Augmented AI: Agentic search
• Economics, Online Markets and Human Computation: Data quality aspects of human-annotated datasets

Abstract

Drawing is a fun and intuitive way to create a character, accessible even to small children. However, animating 2D figure drawings is a much more challenging task, requiring specialized tools and skills. Bringing 2D figures to 3D so they can be animated and consumed in immersive media poses an even greater challenge. Moreover, it is desirable to preserve the unique style and identity of the figure when it is being animated and viewed from different perspectives. In this work, we present an approachable and easy-to-create 2.5D character model and retargeting technique that can apply complex 3D skeletal motion, including rotation within the transverse plane, onto a single childlike figure drawing in a style-preserving manner in realtime. Because our solution is view-dependent, the resulting character is well-suited for animation in both 2D and 3D contexts. We also present a novel annotation study motivating our system design decisions and a pair of user studies validating the usefulness and appeal of our solution. We showcase the generality of our system in a range of 2D and 3D applications.

Problem

• animate 2D childlike drawings
• preserve style in 3D animation
• real-time 2.5D character rigging

Innovation

• 2.5D character model creation
• Realtime 3D skeletal motion application
• Style-preserving animation technique