3D Soft Body Simulation Using Mass-spring System with Internal Pressure Force and Simplified Implicit Integration 

Abstract

In this paper, we propose a method to simulate soft bodies by using gravitational force, spring and damping forces between surface points, and internal molecular pressure forces. We consider a 3D soft body model composed of mesh points that define the body's surface such that the points are connected by springs and influenced by internal molecular pressure forces. These pressure forces have been modeled on gaseous molecular interactions. Simulation of soft body with internal pressure forces is known to become unstable when high constants are used and is averted using an implicit integration method. We propose an approximation to this implicit integration method that considerably reduces the number of computations in the algorithm. Our results show that the proposed method realistically simulates soft bodies and improves performance of the implicit integration method.  

Simulation of Soft Bodies with Pressure Force and the Implicit Method 

Abstract

The implicit approach can be used to efficiently model realistically deformable objects for large constraints such as stiffness or time. In soft bodies with pressure forces, models are composed of mesh points connected by springs and applied with pressure forces. System parameters such as spring constant, damping constant, etc. are defined to describe the behaviors of the deformable objects. Since the simulation of soft bodies with pressure force fails when the constraints are large, this paper proposes the method to solve this problem by using the implicit integration method for soft bodies with particular force. The results show that our method can realistically simulate the soft bodies when large constraints are applied.