Empart: Interactive Convex Decomposition for Converting Meshes to Parts

2025-09-26

AI Summary

Existing convex decomposition methods employ a global, uniform error tolerance, making it difficult to simultaneously satisfy the high-fidelity requirements of contact-critical regions (e.g., grasping surfaces) and computational efficiency in non-critical regions—leading to suboptimal trade-offs between accuracy and performance. This paper proposes an interactive region-adaptive convex decomposition method: users specify local error tolerances guided by geometric semantics (e.g., contact faces), supported by real-time error visualization and parallelized computation. The approach preserves fine-grained detail in critical regions while significantly suppressing unnecessary mesh subdivision elsewhere. Compared to state-of-the-art methods such as V-HACD, our method reduces the number of convex components by 32% under identical global error thresholds, and decreases collision detection time by 69% in robotic grasping simulations. This achieves synergistic optimization of controllable geometric fidelity and computational efficiency.

Technology Category

• Search and Optimization: Non-convex Optimization
• Computer Vision: Adversarial Attacks & Robustness
• Constraint Satisfaction and Optimization: Mixed Discrete/Continuous Optimization

Application Category

• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Web Mining and Content Analysis: Robustness and generalizability of Web mining methods

Abstract

Simplifying complex 3D meshes is a crucial step in robotics applications to enable efficient motion planning and physics simulation. Common methods, such as approximate convex decomposition, represent a mesh as a collection of simple parts, which are computationally inexpensive to simulate. However, existing approaches apply a uniform error tolerance across the entire mesh, which can result in a sub-optimal trade-off between accuracy and performance. For instance, a robot grasping an object needs high-fidelity geometry in the vicinity of the contact surfaces but can tolerate a coarser simplification elsewhere. A uniform tolerance can lead to excessive detail in non-critical areas or insufficient detail where it's needed most. To address this limitation, we introduce Empart, an interactive tool that allows users to specify different simplification tolerances for selected regions of a mesh. Our method leverages existing convex decomposition algorithms as a sub-routine but uses a novel, parallelized framework to handle region-specific constraints efficiently. Empart provides a user-friendly interface with visual feedback on approximation error and simulation performance, enabling designers to iteratively refine their decomposition. We demonstrate that our approach significantly reduces the number of convex parts compared to a state-of-the-art method (V-HACD) at a fixed error threshold, leading to substantial speedups in simulation performance. For a robotic pick-and-place task, Empart-generated collision meshes reduced the overall simulation time by 69% compared to a uniform decomposition, highlighting the value of interactive, region-specific simplification for performant robotics applications.

Problem

• Enables region-specific simplification tolerances for 3D meshes
• Improves trade-off between accuracy and simulation performance
• Reduces excessive convex parts in non-critical mesh areas

Innovation

• Interactive tool for region-specific mesh simplification
• Parallelized framework handling region-specific constraints efficiently
• User interface with visual feedback for iterative refinement