I’m currently experiencing an “out of memory” error when trying to import a large height map into my Unreal Engine project. The crash happens during the import process. I have tried to break down the landscape into 1009x1009 pixel tiles, but the error still persists.
Here are the details of my setup:
Landscape size: 20x20 km
Height map file size: 250 MB
Height map format: PNG/Raw
Unreal Engine version: 5.1
Computer configuration: Intel(R) Core™ i7-10700 CPU @ 2.90GHz, 32GB RAM, 24GB video memory (GeForce RTX 3090Ti), and a 1TB Samsung M2 SSD
Memory paging file set to 200GB
Launching Unreal Engine as administrator
Tried setting process affinity to high
When I check my task manager, my video memory is fully loaded, using all 24GB, and my shared video memory is also fully loaded, using another 24GB, bringing the total to 48GB. My Unreal Engine application crashes as a result.
I would appreciate any suggestions on how to fix this issue. Thank you in advance for your help.
@Jesse_Clark
Close/disable the visual minimap and try again.
By the by, its not ypur PC. The only difference on our main rig is the the processor, as i have an I9. Terrains work/import fine at any tile count/size if you closr the tile window.
@MostHost_LA Thank you very much for your suggestion! I will definitely try disabling the visual minimap and see if that helps. I appreciate your help and will let you know if this resolves the issue. Thank you again for taking the time to respond and offer a possible solution!
If anyone else is having a 3 to 4 hour import run - that’s generally normal for 8km tiles.
However the “out of memory” message refers to Visual memory. Not your RAM.
Vram won’t/shouldn’t be consumed unless the tiles are attempting to load/draw as you go.
Obviously. Opening all tiles at once will crash you by having you run out of Vram…
The import process must be made to not load levels after import - usually by disabling the minimap.
One can totally argue that the process which makes the minimap is trash. You’d be right.
It’s a screencap from the top taken by the engine after it loads the whole level up. Updated in real time.
They could have made an additive system where individual tiles are opened, snapped, and added into the map in like 10 minutes, but no… too much work for epic
Thanks for the detailed explanation, @MostHost_LA! It’s really helpful to understand that the “out of memory” message refers to Visual memory, and not RAM. Also, it’s interesting to know that disabling the minimap could help with the import process. I agree that the implementation of this functionality could be improved. Perhaps an additive system, as you suggested, could make the process smoother and faster. Nevertheless, your input is much appreciated, and I’m glad to have a better understanding of the issue
@MostHost_LA Thanks for the suggestion about disabling the minimap, but unfortunately, the issue still persists even with the minimap turned off. The memory usage during the import process seems to be incredibly high and eventually causes the engine to crash with an out of memory error message. Do you have any other ideas or suggestions for troubleshooting this problem?
You have to make sure levels arent loading as you go.
Otherwise the import will fail wen the Vram hits that limit.
In 4.25 it was literally enough to close the levels/minimap panel out to achieve a succesful import.
If the newer engine versions aren’t working (which is possible ofc), I’d suggest you download something like 4.18 and try the import there (4.18 is before the landscape system was given a the first whack that has made it work badly).
After a succesful import you should be able to upgrade to any engine version (it will literally just be tiles).
I’ll try and do a 200km import in 5.2 just to have a laugh myself…
Also just note that crashing during import is pretty common when dealing with tons of tiles regardless of overall size.
I think my uninterrupted import record was 2211169 tiles.
Obviously the end result was something that couldn’t work just due to the sheer number of drawcalls for impostors (not to mention the size on disk of the levels).
I would also suggest for you to take a look at this guy YouTube tutorial series… he’s done a lot of testing and has a comprehensive explanation about the import process it self .
It’s really helpful to understand that the “out of memory” message refers to Visual memory, and not RAM. Also, it’s interesting to know that disabling the minimap could help with the import process. I agree that the implementation of this functionality could be improved. Perhaps an additive system, as you suggested, could make the process smoother and faster. Nevertheless, your input is much appreciated, and I’m glad to have a better understanding of the issue 
