continue;//If grains of the contacts are both in the reference area, just consider the contact when looping on the first object of the contact. Avoid to take twice a contact into account
}
doubler=p->particles[c->o1].r;
doublexc[DIMENSION];
#if DIMENSION == 2
doublet[DIMENSION]={-c->n[1],c->n[0]};
#else
doublet[DIMENSION]={0,0,0};//TODO when doing 3D friction
doublet[DIMENSION]={0,0,0};//TODO when doing 3D friction -> Nathan