ChangeDimensionPacket

[spring cloak]

This is a problem I couldn't solve a few years ago. I tried moving the player dimension with ChangeDimensionPacket to the nether to display a loading screen. Then after a while, I returned it to the Overworld, which caused chunks to not load, input not working, and so on.

[spring cloak]

solve after 3 years

[summer dove]

Feel free to make it a public plugin 🙂

[spring cloak]

I need to make sure this works in waterdog first as it involves games packet then make it a public plugin

[spring cloak]

1. Command execution — validates dimension name, parses duration (default
   3s), checks player isn't already in a loading cycle. Gets originalDim = 0
   (overworld) and targetDim = 1 (nether). Rejects if same-dimension.

2. Phase 1 — Trigger loading screen — calls sendChangeDimension(player, 1)
   which sends ChangeDimensionPacket(DimensionType.NETHER, player.position).
   This is a direct protocol packet — the player's server-side level never
   changes. The client sees the nether loading screen (purple/red particle
   animation) and clears all chunks from memory. The client starts requesting
   nether chunks from the server, but the server is still in the overworld and
   doesn't respond with nether chunks — the loading screen persists.

3. Wait duration seconds — client sits on the nether loading screen, unable
   to finish loading because no nether chunks arrive.

4. Phase 2 — Switch back — sendChangeDimension(player, 0) sends
   ChangeDimensionPacket(DimensionType.OVERWORLD, player.position). The client
   resets its internal dimension state to overworld and starts requesting
   overworld chunks.

5. Wait 2 ticks (~100ms) — gives the client time to process the second
   ChangeDimensionPacket internally.

6. Phase 3 — Dismiss + chunk refresh — three packets fire in sequence

6A. PlayerActionPacket(CHANGE_DIMENSION_ACK) — tells the client "your
dimension switch is acknowledged, you can proceed to exit the loading
screen". Since we never called switchLevel() or setDimension() on the
server, PNX doesn't send this automatically — we send it manually.

6B. PlayStatusPacket(PLAYER_SPAWN) — tells the client "the player has
spawned". The loading screen dismisses. The client now shows overworld
terrain... but there's nothing visible yet because all chunks were cleared
in step 2

6C. Chunk forcing — player.refreshChunkRender() internally sets view
distance to 1 → 32 → original. Each change triggers the client to
re-negotiate its view radius and request chunks. Then
NetworkChunkPublisherUpdatePacket tells the client exactly where its
rendering center is, which directly triggers chunk requests for positions
around the player. The server's PlayerChunkManager responds by sending the
queued chunks, and the overworld terrain renders.