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4.7 preview 7 lighting very slow (LPV enabled)


i have discover a problem with the dynamical lightning. I have migrated a project from 4.6.1 where a large terrain and some buildings are placed, all builings have dynamical point lights inside. Everything works smooth in 4.6.1 even near or in the buildings with the lights.

After i migrate the project to 4.7 preview 6 the editor stands nearly still cause it lags very heavy i am getting a new picture of the editor like every 20 seconds, if i am near or in a building where point lights are placed. (CPU usage around max. 10 %, RAM is almost complete unused).

All the settings are the same like in 4.6.1 (I am using LPV)

If i disable all light sources it runs smooth again like in 4.6.1. Only one point light is enough to make the editor unuseable. (In unlit mode everything is fine).

I was restarting the whole computer and after loading up the map again i recieve, an error from my placed blueprints in the map that the import of components like billboard component are failed, but everything works in the map. FPS drop from the lightsources is still the same.

I tested only the preview 6 of 4.7 so i dont know if the problem is new in this release.

Thank you.

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asked Feb 11 '15 at 07:50 PM in Bug Reports

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avatar image GreenWolf Feb 13 '15 at 06:25 PM

i just tested the preview 7 of 4.7, the error of loading components is gone.

But the lighting low fps problem is the same, i dont know where de problem is. If i create a new light and play around with the settings i am dont getting any issues, but in my migrated project there is no chance to use point lights.

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Hey GreenWolf, Sorry you're having difficulty with this. I'm definitely interested in tracking down what may be happening here. I've not noticed anything similar with my testing of opening a previous version build with 4.7.

Would you be willing to share the project so I can have a look and see if I see the same results on my end? You can post a link here or shoot me a message via the forums to share privately if you can.

Just to be sure as well, if you create a new project in 4.7 p7 using LPV you do not see this issue, correct?

Also, if you disable LPV for your project that is sluggish does this resolve the issue?

Let me know.

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answered Feb 13 '15 at 08:13 PM

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Tim Hobson ♦♦ STAFF
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avatar image Tim Hobson ♦♦ STAFF Feb 13 '15 at 08:19 PM

I went ahead and edited the title to more clearly reflect what's going on and removed the components failing to import since that appears to be resolved now.

avatar image GreenWolf Feb 14 '15 at 12:32 AM

Thank you,

it seems the error is bound to the map or something in the map (Cant reproduce the error in another map), disable the LPV dont change anything.

If i disable the shadows of the lights i am getting a huge performance boost, and it runs nearly smooth (But not that smooth like in 4.6.1, cause i was leaving the directional light shadows on, maybe that is the reason).

The other thing i can do is remove everything from the map, then the pointlights are working again. I didnt change anything from my 4.6.1 project i only migrate it to 4.7.

I dont really like to upload the whole project cause it will take over 20 hours to upload (very large), if there is no other way i upload it.

edit: Now i have tried a few things, i think it is nothing special with the lights, it is the performance of the landscape and the foliage.

If i delete the landscape or the foliage i can place a lot of pointlights with shadows, but if i add the whole landscape with foliage again the problem is back, the shadows of the lighting only gives the rest.

The Landscape is really massive (Editor Scale tells me its 10km) and there are thousands of foliage instances on it (Not all at once on screen). Everything was working with 4.6.1 (around 50 FPS).

The FPS in 4.7 preview 7 is under 20 fps.

avatar image Tim Hobson ♦♦ STAFF Feb 14 '15 at 04:48 AM

This seems like some information I can work with and see if I can get the same results. With foliage, no matter what build, it's always important to set culling distances for your foliage and if you have a lot that are all casting dynamic shadows that can be problem that kills performance as well.

When I'm back in the office on Monday (Pending weather bc it's apparently may snow here in North Carolina and that will shut the area down. We don't deal well with snow!) I'll be able to run a test with some foliage I have from SpeedTree and with LPV. So no need for the map. I'll get back to you and let you know what I find when I can.

Thanks for your patience! In the mean time to keep working you could just turn viewport real-time off so that you can build and no worry about the FPS chugging.

avatar image GreenWolf Feb 14 '15 at 10:51 AM

Thank you for your help. i hope youre not getting too much snow, be careful.

The point light dont need to be in influence range of any foliage to get the FPS drop, i only need to be near to the point light with dynamic shadows enabled and the landscape with the foliage needs to be in the map.

If i delete the landscape or only the foliage i can place really many point lights without a big performance impact. The other way to get more FPS is to disable the shadows.

avatar image Tim Hobson ♦♦ STAFF Feb 16 '15 at 02:31 AM

No snow yet. really hoping for none! :)

Some other helpful information. I should have put this in the other post.

  • How many instances of foliage are in your scene (You can see the instance count in the foliage tool)?

  • Did you change any of the settings for the foliage tool, such as culling? If so, can you let me know which settings or post a screen shot?

  • What size did you use when you created your Landscape?

This should be enough for me to try and replicate you scene as closely as possible.


avatar image Tim Hobson ♦♦ STAFF Feb 16 '15 at 05:25 PM

Hi GreenWolf,

I've not seen a significant drop in performance that you've indicated.

Here is my test map: ![alt text][1]

As you can see I have a lot of instances going on here. Tree has 1284 Grass has 208,693

In my 4.6.1 project I has a FPS of ~33. In my 4.7 P7 I am getting a FPS of ~57.

In the post process I disabled Eye Adaptation, Bloom, and Lens Flare just to make it easier to see, but this helps with FPS a little.

I also setup a camera in the exact same position and rotation in each project so that I can accurately test.

In the 4.7 project I added 4 point lights that inject light into the LPV. This dropped the FPS down to ~32. I didn't see a radical drop that you mentioned though.

Let me know your thoughts on this.

lpvtestmap.png (1.2 MB)
lpvtestmap.png (1.2 MB)
avatar image GreenWolf Feb 18 '15 at 12:57 AM

Hi Tim, Thank you again :)

At my setting Eye Adaptation, Bloom and Lens Flare is enabled.

My instances are: Trees 147, Big Stones 43,790, Plants 2089. Running around 60 FPS in 4.6.1 with most shadows disabled in the editor (Running game is good playable), in 4.7 with the same settings there will be a huge fps drop.

Enable Shadows of every pointlight in the scene still possible and i can still work in 4.6.1 In 4.7 it is absolutely impossible to enable the pointlight shadows or place a new one with default settings.

Maybe it is the best way if i upload the 4.6.1 project, ill send you the link when its ready (it could take around 20 hours i think, i will start the uploading tomorrow).

There is also a problem where i cannot cook the project with 64bit shipping build or 32bit with development build and i cannot change the icon in the editor for the cooked project (It will always the default UE Icon).

avatar image Tim Hobson ♦♦ STAFF Feb 18 '15 at 04:39 AM

When you upload the project, if you remove the "Saved" folder it will greatly reduce the size of the project.

Typically this will be most of the bloated folder size you see in your project folder. I've had project folders tip in around the 1 gb mark and after getting rid of the backups and saves I didnt need it dropped down to around 200-300 mb.

avatar image GreenWolf Feb 18 '15 at 03:58 PM

Okay i am currently uploading the project it will took now much lesser i think it could be uploaded in 3 - 4 hours. i removed the save folder and it saves me 14 gb.

Btw how can i send you the link private ?

avatar image Tim Hobson ♦♦ STAFF Feb 18 '15 at 04:14 PM

You can send me a message via the forums here: https://forums.unrealengine.com/private.php?do=newpm&u=4894

That really did save a lot of space by getting rid of the backups and saves. :)

avatar image Tim Hobson ♦♦ STAFF Feb 20 '15 at 07:28 PM

Just wanted to give you an update. I didn't get a chance to look at it until today. At the moment anytime I try to open a copy with 4.7 my video driver crashes. Updating my driver does not change that. 4.6 loads just fine, after a while as it takes a few minutes to open.

I'm currently trying to open it with our latest internal QA build which is 4.8. It's loading at the moment, but going VERY slowly. Depending on if this opens for me or not it will be next week before I can hopefully give you some feedback on what I find.

Thanks for your patience while I look into this.

avatar image GreenWolf Feb 20 '15 at 09:20 PM

Thank you for the update.

My video driver never crashed i only get the fps drop in 4.7, i hope that you find out something.

avatar image Tim Hobson ♦♦ STAFF Feb 27 '15 at 07:01 PM

I was finally able to get the project to load without crashing my video driver. I had to migrate all the content from the 4.6.1 project you provided to a blank new project.

Once I did this I was able to load it up and couldn't see the same FPS drop you had mentioned. Everything was actually working slightly better in FPS in 4.7.

You can see the difference here:

alt text

In 4.7 I am getting ~5 fps better performance.

Even placing a single or multiple point lights that all have the settings to default with exception of Dynamic Indirect Lighting checked on doesn't show any side effects.

Can you try migrating all the assets to a new 4.7 project and see if this improves for you?

lpvtest.png (4.6 MB)
avatar image GreenWolf Mar 01 '15 at 03:54 AM

yes migrating everything into a new project seems to fix my problem. I dont know why but something must be wrong with the old project.

Thank you very much !

avatar image Tim Hobson ♦♦ STAFF Mar 01 '15 at 07:01 PM

Awesome! Glad that's working now! Sometimes Migrating to a new project can correct some of these things that may have popped up that aren't reproducible by others. Just like I couldn't open the project without it crashing my video driver until I migrated.

avatar image Mily2206 Mar 02 '15 at 02:10 PM

GreenWolf, could you tell me how did you migrate your project, cause, we are expierencing exactly the same problem, but so far migrating to a new blank 4.7 is not helping - I still get a massive fps drop. I keep receiving a massage that some content did not migrate.

avatar image GreenWolf Mar 02 '15 at 05:11 PM

if something could not migrated then try to reimport the raw files (not the uasset files) to your project.

There is also sometimes a bug where some files are not correct migrated and cause errors(most times with blueprints). Go into your log folder (in your project) and open the newest logfile. Start at the bottom of the file and work from down to the top, there are the errors listed, backup and delete these files which causes errors.

Then start the editor without the error files. If the editor is started you can copy the backups back in there while the editor is started. The editor should instantly refresh the files while running and you can open and correct some errors (if its a blueprint then some nodes are not working anymore, you need to replace them).

Sometimes i was getting a error with some blueprints and they stop me from using the project again until i delete them and correct them then everything was working again.

avatar image Mily2206 Mar 02 '15 at 05:35 PM

Thanks a lot, Ill try it.

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