This hasn't been changed and the same behavior can still be observed in any minecraft version since this was posted. Including the most recent versions.
To give some more context:
I don't think almost anyone would have a problem with this, let alone find out that it works. So I would say it has a very low priority.
The reason I came upon this is because I enjoy the growing parkour side of minecraft. I've made a few courses and upon experimenting with jump length limits, I came upon this.
Two specific jumps that can only be done consistently if you are aware of this mechanic:
1. Sprint jumping on ice to gain speed -> 4 blocks forwards horizontally, 1 block up vertically.
2. Sprint jumping on ice to gain speed -> 6 blocks forwards horizontally, 1 block down vertically.
These jumps are impossible if you hit an area within the red marker from the uploaded image. Within this area you lose some of your momentum.
Jump before the edge, in the blue area, and your momentum is not affected.
My thoughts on why this happens:
Your character barely passes the edge of the ice block, so you no longer stand in it's X or Z coordinate. A bit like you do when you sneak and try to walk off a block. Sneaking or not, you can stand in the adjecent block coordinates while still not falling off a block.
Since you jump while being in an adjecent block coordinate, the game will instead use this block, instead of the ice block, to check for ice when jumping.
TL;DR: You barely cross over into the next block when jumping. While still supported by the ice block, the block under you is air. Air != Ice, so you don't get the speed bonus,
Tobias Rudolph Kolbu
MC-4273
Hi, I'm sorry, but I forgot about this one.
This hasn't been changed and the same behavior can still be observed in any minecraft version since this was posted. Including the most recent versions.
To give some more context:
I don't think almost anyone would have a problem with this, let alone find out that it works. So I would say it has a very low priority.
The reason I came upon this is because I enjoy the growing parkour side of minecraft. I've made a few courses and upon experimenting with jump length limits, I came upon this.
Two specific jumps that can only be done consistently if you are aware of this mechanic:
1. Sprint jumping on ice to gain speed -> 4 blocks forwards horizontally, 1 block up vertically.
2. Sprint jumping on ice to gain speed -> 6 blocks forwards horizontally, 1 block down vertically.
These jumps are impossible if you hit an area within the red marker from the uploaded image. Within this area you lose some of your momentum.
Jump before the edge, in the blue area, and your momentum is not affected.
My thoughts on why this happens:
Your character barely passes the edge of the ice block, so you no longer stand in it's X or Z coordinate. A bit like you do when you sneak and try to walk off a block. Sneaking or not, you can stand in the adjecent block coordinates while still not falling off a block.
Since you jump while being in an adjecent block coordinate, the game will instead use this block, instead of the ice block, to check for ice when jumping.
TL;DR: You barely cross over into the next block when jumping. While still supported by the ice block, the block under you is air. Air != Ice, so you don't get the speed bonus,