[MC-89263] Blocks will not visually update unless looking downwards

This seems to be happening in my world file but I cannot not reproduce it in a new world. I have tried to pinpoint what is causing it but the only thing that seems to fix the bug, is looking down.

Watch video to see what I mean:
https://youtu.be/Jg1dWh1XkRk

I have included the world file I used in the video to reproduce the bug.
Teleport to X:240 Y:52 Z:307 and stand on bookshelf to view bug occur as in video.

/tp @p 240 52 307

Further testing proved the blocks are updating but not visually, as I can pick-block when the ice is supposed to turn in to redstone block, and I will get a redstone block, but Minecraft will show ice.

Linked issues

relates to 1

MC-89262 Block lag / Door delay / Pressure plate stuck Resolved

Attachments

Block Update Bug - 15w39b.zip

Comments 16

[Mod] Neko 2015-09-22T00:23:17Z

~~Cannot reproduce in given world. May just be block lag on your computer?~~ After boosting my render distance it seems to be a lot more common. Can confirm.

qmagnet 2015-09-22T00:31:00Z

I don't think so because the bug doesn't occur on my PC in 15w38b.

[Mod] Neko 2015-09-22T00:32:22Z

qmagnet 2015-09-22T00:34:34Z

Hmmmm, I don't know. If you watch my video, it's not that it's lagging, it's not updating at all. But it could be related.

Also, there's no issue when I look downwards.

kumasasa 2015-09-22T06:33:06Z

Can confirm from certain angles.
When loading the world for the first time, the screen stays blank except the redstone particles.

6 more comments

cj 2015-09-22T19:08:47Z

This is very noticable with a large render distance. I had a piston running on a clock, which often didn't update at all for a few seconds.

(Warning: pure speculation below)
I think it's got something to do with Dinnerbone moving local chunk rendering to a seperate thread along with all the other chunks, which is likely to not be noticable when only a few chunks have to be rendered (i.e. when looking down), as the chunk-render thread would finish its work before the frame is rendered. however, if the workload increases, the thread might not be able to finish its work in time.

qmagnet 2015-09-22T19:16:54Z

@cj, did you have this bug in your own world, or just the one I posted?

cj 2015-09-22T19:29:30Z

I did have it in my own world. I had a simple setup with a 2 hopper clock (see https://youtu.be/bYwzd62cLSw?t=1m5s), and the pistons and redstone didn't visually update. The piston sounds did play regularly, as expected and according to the clock's speed, so it really only effects rendering.

The render distance was set to 32 when this occurred, and as a workaround I turned the render distance down to 16 chunks, which seemed to fix it for me, as well as looking down.

[Mod] redstonehelper 2015-09-23T13:21:39Z

Does your issue still occur in 15w39c?

[Mod] Neko 2015-09-23T13:31:36Z

Notes from the snapshot blog post

Update: We’ve released 15w39c. Redstone contraptions should visually update much faster again, and performance should be better on older computers.

[Mod] Neko 2015-09-23T13:33:43Z

Still occurring with given world file in 39c.

ThePhysician2000 2015-09-24T17:44:29Z

Confirmed for 15w39c. It seems to only happen when a Redstone contraption is running.

kumasasa 2015-10-04T07:17:44Z

Can no longer confirm in 15w40b.

qmagnet 2015-10-07T00:42:26Z