A simple straw of Grass can be modelled as a row of particles, like pearls on a string. Structural springs and bending springs are inserted to provide the string with stiffnes. The Structural springs connect neighbour particals and the bending springs connect not direct neighbours but particles from the same neighborhood. On a string of particles forming a grass this means a connection between a particle and the neighbour of his neigbour. If more stiffness is wanted, bending strings to farther neighbours can be added.