* Set the kill-z of the scene using a value in a template stream function.
* Assign a value to kill-z using world.setKillZ(value) or world.setKillZ!"="(value).
* Increment kill-z by value using world.setKillZ!"+="(value).
* Decrement kill-z by value using world.setKillZ!"-="(value).
* Multiply kill-z by value using world.setKillZ!"*="(value).
* Divide kill-z by value using world.setKillZ!"/="(value).
* Returns reference to this so it can be used in a stream.
* Set the kill-z of the scene using a value in a template stream function. * Assign a value to kill-z using world.setKillZ(value) or world.setKillZ!"="(value). * Increment kill-z by value using world.setKillZ!"+="(value). * Decrement kill-z by value using world.setKillZ!"-="(value). * Multiply kill-z by value using world.setKillZ!"*="(value). * Divide kill-z by value using world.setKillZ!"/="(value). * Returns reference to this so it can be used in a stream.