Long Range Attachments - A Method to Simulate Inextensible Clothing in Computer Games

Abstract

Inextensibility is one of the most fundamental properties of cloth. Existing approaches to handle inextensibility often require solving global non-linear systems and remain computationally expensive for computer game uses. Real time performance can be achieved by allowing damping or stretching at reduced solver costs, but these compromise visual realism - the cloth either looks stretchy or fine wrinkles get lost. Our long range attachment (LRA) method exploits that typical game character clothing tends to be attached to some kinematic parts of the character. LRA method applies unilateral distance constraint between free particles of the cloth to distant attachment point on the character, preventing them from stretching away from the kinematically driven attachments (e.g. shoulder for a cape). This simple step provides an efficient shortcut for enforcing global inextensibility that can be readily implemented into existing game physics methods such as PBD.