Uploaded image for project: 'Minecraft: Java Edition'
  1. Minecraft: Java Edition
  2. MC-213779

FPS drops when looking up in a tall world (4064 blocks)

    • Icon: Bug Bug
    • Resolution: Fixed
    • 21w37a
    • 1.16.4, (14)
      20w51a, 21w03a, 1.16.5, 21w05a, 21w05b, 21w06a, 21w07a, 21w08b, 21w10a, 21w11a, 21w14a, 21w15a, 1.17 Pre-release 3, 1.17
    • None
    • Confirmed
    • Performance, Rendering
    • Important

      The bug

      If you generate a tall world using custom world files, looking up(or down when far away from min_y) decreases fps by a very high amount without there being a lot to render

      To reproduce

      1. Load the custom world in the attachments
      2. Look up
        →  FPS drops dramatically

      In 21w06a the total world height got increased to 384 by default, this issue now also occurs(less extreme, the world height is still lower than my custom world) by default in new worlds

          [MC-213779] FPS drops when looking up in a tall world (4064 blocks)

          Can confirm in 1.17.1. This actually happens in regular worlds as well. For example, while looking down in the bottom of the nether, I get about 98 FPS, which promptly drops to about 52 when I look up.

          [Mod] ampolive added a comment - Can confirm in 1.17.1. This actually happens in regular worlds as well. For example, while looking down in the bottom of the nether, I get about 98 FPS, which promptly drops to about 52 when I look up.

          The older versions were transferred from MC-210916, see that ticket for details.

          [Mod] violine1101 added a comment - The older versions were transferred from MC-210916 , see that ticket for details.

          BBLZ added a comment -

          I just noticed there are affected versions attached that don't even support datapacks increasing world height. Isnt this bug only noticeable in worlds with increased height?

          BBLZ added a comment - I just noticed there are affected versions attached that don't even support datapacks increasing world height. Isnt this bug only noticeable in worlds with increased height?

          Considering that world height is 256 blocks and will be increased to 384, chunk rendering algorithm might need update that limits chunks and subchunks being rendered not only horizontally, but also vertically. 384 meters is similar distance to 24 chunks that need to render. Since default rendering distance is set to 12 or so, most of far area will be rendered as gray matter hidden by fog anyway. Solution for this would be limiting rendering to sphare of render distance instead of full world-height cube. Considering it needs to render only area in front, we can limit sphare to cone gaining quite good performance boost.

          [Helper] Michał added a comment - Considering that world height is 256 blocks and will be increased to 384, chunk rendering algorithm might need update that limits chunks and subchunks being rendered not only horizontally, but also vertically. 384 meters is similar distance to 24 chunks that need to render. Since default rendering distance is set to 12 or so, most of far area will be rendered as gray matter hidden by fog anyway. Solution for this would be limiting rendering to sphare of render distance instead of full world-height cube. Considering it needs to render only area in front, we can limit sphare to cone gaining quite good performance boost.

            jeffmck [Mojang] Jeff McKune
            Tycho Los BBLZ
            Votes:
            19 Vote for this issue
            Watchers:
            16 Start watching this issue

              Created:
              Updated:
              Resolved:
              CHK: