When using a 1.21.2 or newer client to connect to a 1.20.6 server, there is an issue with incorrect Y-axis rotation on displays.

[RICE0707]

'/viaversion dump' Output

https://dump.viaversion.com/fe954458f1a1edcf024eafc37f8ba2dbd5edbe4b52c9eb316af738e0dbfb77bb

Server/Client Error

none

Bug Description

In 1.21.2+ clients connected to a 1.20.6 server, adjusting the Y-axis rotation of item displays does not render correctly when the angle exceeds 90° or -90°. The rotation between 90°180° and -90°-180° fails to display properly.

Steps to Reproduce

Attempt to rotate an item display by setting its angle using the setPitch and setYaw methods from a regular entity (via this custom plugin: ModernShowcase.

Then observe the display angle using both a 1.20.6 client and a 1.21.2+ client.

Expected Behavior

On a 1.20.6 client, the item display renders as expected. However, on a 1.21.2 or newer client, the display fails to show Y-axis rotations beyond ±90°, making 90°–180° and -90°–-180° rotations visually incorrect or absent.

1.20.6 https://github.com/user-attachments/assets/dff5d906-0760-4674-8545-42c6ceb22422

1.21.2 https://github.com/user-attachments/assets/4d1fbafc-ae98-4ebf-9893-7233b43b77cc

Additional Server Info

No response

Checklist

• [x] Via plugins are only running on EITHER the backend servers (e.g. Paper) OR the proxy (e.g. Velocity), not on both.
• [x] I have included a ViaVersion dump.
• [x] If applicable, I have included a paste (not a screenshot) of the error.
• [x] I have tried a build from https://ci.viaversion.com/ and the issue still persists.