[MCM-977] Some particle effects will play multiple times if the game refreshes

Partner Rank:

Partner Team Reporting:

Gamemode One

Verification builds and Platforms:

Ver. 1.4.30, Build 3678058, Windows 10

Summary:

When using particles on an animation controllers played off an entity. It is possible to create duplicates of the same particles played off an animation controller. Only when minecraft re-initializes.

Impact:

It will heavily impact particle visuals in our latest content. Especially if a particle is constant, never expires or runs for a very long time.

Reproduction:

Open the provided world and ensure the provided RP and BP are enabled.
Observe the circling particle overhead.
Alt-tab away from the Minecraft client.
Wait about a minute (or a couple minutes. Required wait time seems to depend on device).
When you come back to minecraft if the white loading screen pops up you’ve followed the steps correctly. If the white loading screen did not appear, alt-tab and repeat step 4, (Maybe for longer).
Look for a second instance of the particle.

Observed Results:

A second instance of the particle is created and moves alongside the first.

Expected Results:

Only one instance of this particle exists at any given time.

Screenshots / Videos attached:

I have attached a Behavior pack, resource pack, and world to help demonstrate this issue.

I have also attached a screenshot of the white loading screen that appears when the Minecraft window is brought back into focus and a screenshot of two particles being created after the bug is reproduced correctly.

Notes:

My best guess would be this occurs because the animation controller runs itself a second time after minecraft reinitializes OR the entity is re-summoned because the game has been idle for too long and this causes the particle to summon again, but the initial emitter lingers as well.

The game seems to only perform this refresh when the BP/RP is a large enough size. Near-empty packs will not prompt this refresh in the same amount of time.