A Real-time Hair Simulation Method With Heptadiagonal Decomposition On Mass Spring System

Simulating the detailed dynamics of hairs in real time is still a challenge problem in graphics due to the sheer number of strands and their complicated dynamics and self collisions.Previous interactive solutions either simplify the strand dynamics or reduce the DoFs in simulation at the cost of rich motion details.In this paper,we present a real-time simulation method for animating hair with full motion details.Our method is aimed at efficiently capturing the inextensibility,bending and torsion strand mechanics while presenting the stiction/repulsion and detailed collision effects in a real-time time budget.We utilize the local structure in the Selle mass spring model and provide a fast implicit integration method based on heptadiagonal matrix decomposition in R3,which provides two to three orders of magnitude of ac-celeration to the original iterative-based approach like PCG.For efficiently capturing self interactions,we factorize the phenomenon into a coarse,glob-ally coupled volumetric and a detailed collision view.The coarse behaviors are solved with an Eulerian method based on position based density con-trol,while detailed collisions are efficiently handled with temporal coherent link update.Our method can faithfully simulate detailed hair motions in-teractively using desktop computer and is robust to various hair styles.We evaluate the efficiency and effectiveness of our method for simulating variant motions of the hair in different styles.