  We consider perfect simulation algorithms for locally stable point processes
based on dominated coupling from the past. A version of the algorithm is
developed which is feasible for processes which are neither purely attractive
nor purely repulsive. Such processes include multiscale area-interaction
processes, which are capable of modelling point patterns whose clustering
structure varies across scales. We prove correctness of the algorithm and
existence of these processes. An application to the redwood seedlings data is
discussed.
