This video, titled ‘Minecraft : Fixing spawn in high altitude mob traps’, was uploaded by Kiershar on 2012-03-28 05:35:54. It has garnered 106689 views and 768 likes. The duration of the video is 00:02:45 or 165 seconds.
Your mob trap doesn’t spawn monsters? Add an antenna to it!
Here’s how it works i think : To get mobs to spawn in chunks above y128 you need to have stuff built in the chunks above them. Making an antenna that covers all the chunk above your mob trap enables the spawning algorithm to shuffle through the chunks that contains your mob trap. In programmer speak : Probably the algorithm was planned to skip chunks with nothing built in for optimization aka making the code faster. My guess is that there’s an offset error of 1 on the Y coord when checking chunk.
Also it makes sense that mobs don’t spawn above 240, because the algorithm never shuffles through the top chunk because its impossible to build above it.
Kind of mob traps that may have those problems : Flushing mobtrap : http://www.youtube.com/watch?v=2yhe8ptSAIc Mobtrap with minecart : http://www.youtube.com/watch?v=o7HuJQjoyBY
