# Unreal API thread safety

**URL:** <https://forums.unrealengine.com/t/unreal-api-thread-safety/33950>\
**Category:** C++\
**Tags:** unreal-engine\
**Created:** [June 30, 2015, 7:43pm UTC](https://forums.unrealengine.com/t/unreal-api-thread-safety/33950 "2015-06-30T19:43:21Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![anonymous\_user\_3ae9789f](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_3ae9789f](https://forums.unrealengine.com/u/anonymous_user_3ae9789f)\
**Post date:** [June 30, 2015, 7:43pm UTC](https://forums.unrealengine.com/t/unreal-api-thread-safety/33950/1 "2015-06-30T19:43:21Z")

</div>

Hi there,

Is it possible to parallelize Unreal API functions, such as raycasts?

Thanks in advance,

---

<div class="post-metadata">

**Author:** ![anonymous\_user\_3ae9789f](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_3ae9789f](https://forums.unrealengine.com/u/anonymous_user_3ae9789f)\
**Post date:** [July 2, 2015, 6:56am UTC](https://forums.unrealengine.com/t/unreal-api-thread-safety/33950/2 "2015-07-02T06:56:27Z")

</div>

Helloooow anyone ?

---

<div class="post-metadata">

**Author:** ![Jambax](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/jambax/32/904177_2.png) [@Jambax](https://forums.unrealengine.com/u/Jambax)\
**Post date:** [July 2, 2015, 7:40am UTC](https://forums.unrealengine.com/t/unreal-api-thread-safety/33950/3 "2015-07-02T07:40:39Z")

</div>

I know very little about this, other than I’m fairly certain that any collision-based items such as traces have to be done as part of the Game Thread.

Somebody like Rama, CMartel or JamesG would know better though, I’ve honestly not used Multi-Threading in UE4 yet. There are a couple of tutorials from Rama here on Multi-Threading though just in case you haven’t seen them yet:

> **[A new, community-hosted Unreal Engine Wiki](https://forums.unrealengine.com/t/a-new-community-hosted-unreal-engine-wiki/141494)**
>
> After over a year in maintenance mode, the official Unreal Engine Wiki is now permanently offline. These resources now live on a new community-run Unreal Engine Community Wiki — ue4community.wiki! You will be able to find content from the official...

> **[A new, community-hosted Unreal Engine Wiki](https://forums.unrealengine.com/t/a-new-community-hosted-unreal-engine-wiki/141494)**
>
> After over a year in maintenance mode, the official Unreal Engine Wiki is now permanently offline. These resources now live on a new community-run Unreal Engine Community Wiki — ue4community.wiki! You will be able to find content from the official...

---

<div class="post-metadata">

**Author:** ![anonymous\_user\_10b2fd67](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_10b2fd67](https://forums.unrealengine.com/u/anonymous_user_10b2fd67)\
**Post date:** [July 2, 2015, 2:02pm UTC](https://forums.unrealengine.com/t/unreal-api-thread-safety/33950/4 "2015-07-02T14:02:32Z")

</div>

My thought would be try it and see what happens. It looks like PhysX supports it I’d be shocked if this functionality wasn’t on the roadmap somewhere, so it would be nice to know if this is already a planned feature or not.

---

<div class="post-metadata">

**Author:** ![anonymous\_user\_39dfe35e](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_39dfe35e](https://forums.unrealengine.com/u/anonymous_user_39dfe35e)\
**Post date:** [July 2, 2015, 4:13pm UTC](https://forums.unrealengine.com/t/unreal-api-thread-safety/33950/5 "2015-07-02T16:13:00Z")

</div>

I think PhysX is already multi-threaded in UE with the async scene. It does does not work as well as in Unity, but it seems they are on it