query.delta_time sometimes returns negative in player animations

*Partner Rank:*

2

*Partner Team Reporting:*

Everbloom Studios

*Verification builds:*

1.13.0.2 (MCM-804 and MCM-805 make it difficult to test in builds 1.13.0.4 through 1.13.0.10)

*Summary:*

The MoLang function query.delta_time will sometimes return negative values when called from player animations.

*Impact:*

Lengthy player animations that don't rely on another timekeeping system (such as query.life_time) appear to stutter a lot of the time. This also causes sound effects, particle effects and events in the animation's timeline to play more than once.

Note that for a lot of reasons, we can't always bind the animation time to query.life_time to get around this, as some animations use complex anim_time_update expressions that just can't be translated to query.life_time or other server-controlled variables.

This does not occur with animations applied to non-player entities.

*Repro Steps:*

1. Create and join the provided world. Move around for a few seconds.
2. Exit the world and open the latest Debug_Log txt file in the game's log files. query.delta_time should have been logged for every frame you were playing.

*Observed Results:*

You will see some logged values go into the negatives. This makes the animation time rewind at some points.

*Expected Results:*

All logged values should be positive.

*Screenshots/Videos attached: Yes/No*

Yes

A screenshot has been attached showing logged delta_time values, a few of them less than zero.

*Regression Builds:*

Unknown