Method for simulating collisions

A method of conducting a computerized simulation of a collision between a first body and a second body, the method comprising:

• providing a first three dimensional mesh in the form of the first body, and a second three dimensional mesh in the form of the second body, each of the meshes being formed of nodes and surface elements, and having a respective deformation relationship relating a fore required to cause a deformation in a region of the mesh;
• moving the metes until a collision is detected;
• and
• calculating a series of positions of the meshes during the collision, each position being based on a prior calculated position, wherein calculating the series of positions includes:
• alternating between (1) the fist mesh as a master mesh and the second mesh as a slave mesh, and (2) the second mesh as a master mesh and the first mesh as a slave mesh the master mesh having master surface elements and the slave mesh having slave nodes;
• for each of a plurality of slave nodes:
• (1) detecting penetration of a master surface element by the slave node;
• (2) deforming the penetrating slave node a deformation distance to lie adjacent master mesh;
• (3) calculating a local deformation collision force acting on the penetrating slave node based on the deformation distance and the deformation relationship for the slave mesh;
• summing the local deformation collision forces for the plurality of penetrating slave nodes, thereby calculating a general collision force;
• applying the generalized collision force to the slave met;
• moving the slave mesh to a next position based on the generalized collision force.

A method for conducting a computerized simulation of a collision between a vehicle and an object, the method comprising:

• defining a vehicle mesh of surface elements and nodes, the vehicle mesh being in the shape of the vehicle;
• defining an object mesh of surface elements and nodes, the object mesh being in the shape of the object;
• assigning a respective deformation relationship to each of the vehicle and object meshes, each deformation relationship relating a force required to cause a deformation in a region of the associated mesh;
• assigning a respective restitution relationship to each of the vehicle and object meshes, each restitution relationship describing the distance a deformed region of the associated mesh will restitute after being deformed;
• moving the meshes until a collision is detected;
• and
• calculating a series of positions of the meshes during the collision, each position being based on a prior calculated position, wherein calculating the series of positions includes:
• over a plurality of timesteps, alternating between (1) the vehicle mesh as a master mesh and the object mesh as a slave mesh, and (2) the object mesh as a master mesh and the vehicle mesh as a slave mesh, the master mesh having master surface elements and the slave mesh having slave nodes;
• at each timestep, for each of a plurality slave nodes on the slave mesh:
• (1) determining whether the slave node has penetrated a maser surface element and therefore should be deformed, and if so, (a) deforming the slave node a deformation distance to lie adjacent the maser mesh and (b) calculating a local deformation collision force acting on the slave node based on the deformation distance and the deformation relationship of the slave mesh;
• (2) determining whether the slave node should be restituted, and if so, restituting the slave node and deter whether a restitution collision has occurred, and if so, calculating a local restitution collision force acting on the slave node;
• calculating a generalized collision force based on the local deformation and restitution collision forces acting at each slave node;
• applying the generalized collision force to the slave mesh;
• and
• moving the slave mesh to a next position based on the generalized collision force.