Here is a space-time picture of the evolution of a system of 500 particles in one dimension which undergo inelastic collisions, with restitution coefficient r=0.9 up to time=600. As a time-saving feature, if the relative velocity between 2 collision partners is less than 0.01, a purely elastic collision is implemented. For more details see Shock-Like Dynamics of Inelastic Gases,
E. Ben-Naim, S. Y. Chen, G. D. Doolen, and S. Redner, Phys. Rev. Lett. 83, 4069-4072 (1999); (cond-mat/9909354).