|group||The group index (ID) of the particle group to count.|
This function will return the number of particles that are
active in a single group. The group index (ID) is the value that is
returned when you call the function physics_particle_group_end().
gp_num = physics_particle_group_count(group1);
The above code will get the number of particles used to make the group indexed in the variable "group1" and store the value in a variable.