The altimeter is a new item that gives the altitude of the player from a specific y value.

Appearance

Similar to the clock and the compass, probably will a copper thing inside.

Crafting

[TBD] might need copper

Usages

• Holding the item will display the value above the hotbar.
• Pointing at the item in the inventory will also display its value in the item's lore lines.
• Right-clicking the item will bind its original value to the clicked block's y position.
• Shift + Right-clicking the item will set its original value to 0.0.

Value and Fluctuation

The value will be expressed with a decimal value (only up to one decimal will be stocked). It will be equal to the difference between the y level of the player and the original value.
To make it more realistic, it will not be precise: it will fluctuate above and under the actual value from zero to the current amount of fluctuation.

Maximum amount of fluctuation

• In the Overworld, the futher it is from the ocean level, the more it will fluctuate. (from 0.1 to 1.75)
• In the Nether, the further it is from the nether bedrock roof, the more it will fluctuate. (from 1.85 to 3)
• In the Ender
  • it will be set to 10 on the main island if the dragon is present
  • it will be contantly be 0.1 on the main island w/o the dragon or on the outer islands
• In other dimensions, [TBD]

Examples:
At the sea level of the Overworld (y=62), the value will fluctuate between 61.9 and 62.1
At the bottom of the Overworld (y=-64), the value will fluctuate between -65.75 and -62.25