Steps to reproduce
Load the test world. [mediaInline] This world is a void soulsand valley with a small build of netherrack, glass, slabs, and light-producing blocks in an arrangements that showcases the issue.
Position yourself directly under the tinted glass block, or stand on the glowstone block, and watch the build for ghast spawns.
Expected results
If any ghasts spawn, they would not spawn stuck inside blocks.
Observed results
Ghasts spawn encased in solid blocks or trapped inside the glass platform with no blocks underneath them.
Analysis
During environmental spawn attempts the game checks whether spawning a mob would cause it to collide with solid blocks. It does this in two steps:
First the game checks for blocks whose material is SolidBlocking in the coordinate spaces where the mob's bounding box would extend.
If the first check returns true, then the game it checks whether the mob's bounding box would overlap the hit/collision box of any blocks.
The fact that the second check is conditional on the first allows mobs to spawn in places where their bounding box overlaps with blocks like leaves, glass, and normal ice, which have collision even though their material is not SolidBlocking (see MCPE-47846). When a spawned mob collides with these blocks its position may be instantly offset, which some players refer to as "instapush". Various farms have been designed based on spawning mobs partially inside non-solid blocks and/or instapush.
With ghasts the instapush offset may be up to 5 blocks hoziontal and 2 blocks vertical and may place the ghast in a position where it overlaps "solid" (= unit cube collision and SolidBlocking material) blocks. If a ghast has solid blocks around its mouth it immediately suffocates. The extreme instapush of ghasts seems to be related to is large collision box and the collision of blocks nearby the spawn spot. Instapush for any other mob is usually only 1 block in any direction.
Ghast spawn in Side of solid blocks, I made a solid 4x4x4 cube to block spawn and they still spawn INSIDE THE CUBE they suffocate and die but still spawn in it. They spawn in my ice paths that are only two blocks high clearly there is a problem that needs to be fixed
Linked issues
is duplicated by 1
relates to 2
Attachments
Comments 32
There is not a single solid block below it
The other blocks in the area have redstone on top of it even the ice
So if they can spawn inside of glass and it pushes them why can’t this be fixed where the glass being inside this space 5x5x5 above a single spawn block prevents spawn
It’s up to the developers whether, how, and when to fix bugs or redesign game mechanics. I am just a bug tracker moderator. The moderators and helpers on the bug tracker are volunteer staff who help to clarify and confirm reports. I have confirmed this one. Today it has been assigned an ADO number by Mojang, which means they are tracking the issue internally.
So found the spot it’s an observer that has one block of air above it with the glass ceiling and it is spawn pushed 6-8 blocks east
Well hopefully they have the glass do something to prevent that because I like my area is looking open, not cluttered with extra blocks
Natural spawns in Bedrock Edition require a solid block or top slab or ice with air (or some collisionless blocks like flowers) directly above it. The spawn gets attempted on top of that block. For the attempt to succeed the collision box of the mob must not overlap the collision box of any solid-material block. That means mobs may spawn with part of their bodies inside of blocks like glass and leaves as long as there is a solid block (or top slab or ice) that they are spawning on top of. To prevent the ghasts from spawning you will need to either remove the spawnable block, or place a solid material block (something like wood, stone, metal or wool) somewhere in the 5x4x5 space above it. Many decorative blocks like fences and buttons can be used for collision based spawn proofing.
Does this help with your issue? If you still think there is a bug, could you try to get a better screenshot that shows the space where ghasts spawn when there is not a ghast obstructing the view?