(1) Do NOT use global variables !
(2) [How to] Post correctly formatted and colorized code on the forum?
(3) Use 2 space indentation, not tabs.
(4) Use a space before and after operators.
(5) Ruby is an English programming language and this forum is an English forum.
If you use English comments within your code, we can better understand what the code is trying to do.
(6) The API asks you to use view.invalidate, not view.refresh.
(7) There is a method call buat_pondasi_tapak() that we do not know what it does.
(8) The following is a very poor coding pattern:
entities.each { |entity| entities.erase_entities entity }
… when you can use …
entities.erase_entities(entities.to_a)
… or even simply …
entities.clear!