phent_addobstruction(ENTITY* entity*, var amount, VECTOR* vecpoint)
Obstructions limit or prevent waves from propagating past them. This
function only works with PH_WAVE entities.
||the entity to be affected
||strength of obstruction with a range of 0..1 where 1 means block waves and 0 does not limit waves at all.
||a global (=world) coordinate where an (invisible)
obstruction should be placed.
Returns:1 if successful, 0 otherwise.
Ideally obstructions should be anti-aliased, meaning that there is a
center point with amount set to 1 and then a border zone of 3 vertices
where the amount value is set to less than 1. If amount is set to a
negative number all previous obstructions of this entity will be
phent_addobstruction(my, 0.1, my.x)