Blueprint performance bug

Hey guys. Think I’ve found a bug with 4.6.1

I’ve been working on some steering behavior code in blueprint for a new tutorial and I came across something a bit weird.

I’m doing a lot of blueprint code during ticks to calculate local steering vectors and the like. You can see a video of what I’m talking about here:

Anyway, its not so much the performance during playtime that I think is a bug. Its that the editor itself slows down after the scene has been played in editor and never speeds back up again. Almost like something in blueprint is being maintained in memory and ticked after the PIE session ends.

If I exit the editor and restart it, I’m back up to the normal framerate. So its basically the fact that it has been played that is causing the issue.

I’m happy to share the whole project if that helps (its literally a few blueprints and a single mesh).

Obviously I’m not worried about the poor performance during playtime, thats something I’m going to address myself. But I expect the runtime scene to be completely unloaded when I end the PIE session and it appears that isn’t the case. Maybe some GC issue? I dunno.

Ta.

Phil.

Blueprint is not very good for tick code

Blueprint is not very good for tick

Seriously?

I’m working on a UE4 project created from a c++ template, because I think I’ll put some code at some point but…until now… I don’t have a single line of custom code in this project, everything is runninjg from BP… either class, anim or controllers. My current scene is not that big but already involves more than a few different animated components, automated and player controlled as well. sounds, effects,…etc. I’m already impressed by what I can do without using a single line of code…

I don’t think that BP is not good for tick, I just think that the editor has become less stable and the memory usage, as ** pointed, likes to make jokes since 4.[4|5].

I’m aware that BP runtime perf is slower compared to equivalent c++ implementation, there is overhead of course but I prefer to implement gameplay components using BP as much as possible, seeing all advantages we have by using them… As soon as performance starts to become an issue then I’ll check where and how I can add improvements and if required, switch some BP (or specific functionalities used in BP) to c++ if needed.

@
UE4.6.1 seems already better than 4.5 was, regarding memory and stabilty but still not as stable as pre UE4.4. I’ve not tested 4.7 but I’m sure that Epic devs ( as well as community!) are working hard to improve the editor stabilty and perf :wink:

Hi ,

I’d be more than happy to take a look at the project to see what may be going on. If you open up your task manager and run the project as you describe, do you see a spike in the amount of memory being used?

Thanks ,

Here’s a link to the project:

https://dl.dropboxusercontent.com/u/15474677/Epic/FishyFishyFishyOh.

I deleted saved and intermediate dirs, not sure if thats safe to do, but I should hope so. This is a 4.6.1 project, blueprint only, with only a single mesh asset and a couple blueprints.

BTW: I know this is going to be slow, I was literally just testing something. What concerns me is the editor slowdown when PIE exits.

Ta!

Hi ,

I was able to reproduce this error and have entered a bug report, UE-7172 to be assessed by the development staff.