Hi!
I’m running out of RAM when I’m building the light (preview quality). I have 32 gb and I thought that would be enough but
unfortunately not.
I need to know what’s most RAM consuming in Unreal so I can optimize my project.
The meshes/polycount?
The lightmap resolution?
The texture resolution?
Thanks in advance!
Textures, when you’re building lighting it’ll be the lightmaps, since it has to load all of the lightmaps in the level. It can be especially bad when you’ve got foliage. That’s why in games when the levels get big enough they don’t use lightmaps.
Geometry would be second, but it won’t be as bad because while it does need all of the meshes at the highest LOD loaded it can still keep one copy in memory when it’s been reused more than once. For lightmaps it has to have a lightmap for every object even if it’s a duplicate. And regular textures can still be loaded once in memory as well even if it’s used on multiple objects.
Thank you!! 
@darthviper107 wouldn’t anyone just split the level into different levels, load them separately and build them separately? I always assumed the reason for not using lightmap is that they become pointless with a day/night cycle system that most games implement…
To answer your question about ram usage,
When building lights you can ran out of 64Gb. However unlike in other things, the process is taken outside of unreal and has a whole different application that can allow you to even split the load between different PCs.
Check into the Swarm docs.
You could split up the map to build them separately, but doing that based off lightmap usage would be an annoying thing to have to deal with. You also need to consider how big the game install will be.
Also note, using Swarm to split up the lighting build onto multiple machines does not reduce memory usage, it still needs to load all of the assets on each machine, it just renders faster.
I mean, if you take any AAA game of the last decade or so the file size can even get above 90GB.
Seems to me like… it would be nice if someone other than us indy devs actually gave any of that some consideration.
And yes, swarm doesn’t split ram usage, when I say load I mean processing load towards total completion.
meaning the OP would be better off adding more ram anyway, however its not a need like it would be if you attempted to load 20 tiles or so…
Do you think that people are most likely to be OK with installing a new Indie game that’s 100GB or the latest Call of Duty that’s 100GB?
Good question. I think it depends who it is, though, and what they’re looking for in a game. Maybe most people would rather play an indie game at 100 GB if the features and aspects of the game are more interesting and deeper than a typical AAA title. The problem with COD and Mortal Kombat, and such, is the updates add more and more, increasing the GB use to stupid amounts. And it’s not that much extra content. I play COD: MW (the newest one), and Battlefield 5, and both of those games add a new map or two, a few new characters / models, and some appearance items like clothing and gun textures in one quarterly update…and I’m asking the question: how does that amount to 25+ additional GB of space usage?? All I have is a 1 GB ssd, and a 500 GB PS4 (not Pro), and I’m surprised I haven’t run out of drive memory with the other games I have stored (lots of which were made using Unreal Engine). The Surge uses up far less space, yet it has quite detailed levels, and is a rather long game. So how does the levels in it being separately loaded differ from the separate maps in COD:MW and Battlefield 5? Not even Dragon Age: Inquisition or Horizon: Zero Dawn use the amount of space that two of the most popular FPS games do.
The devs that work for the companies literally don’t care about file size.
I have never met a single game developer (in AAA, indie, virtual worlds, or edu-gaming) where file size wasn’t a HUGE DEAL.
There is always a budget. Everyone does everything they can to stay within that budget. There are tons of reasons why this is still the case for modern games, including “files that are too big don’t fit in console RAM or in GPU memory.”
You may know different developers and different companies, or maybe you just don’t agree with the method they use to set the budget, but “don’t care about file size” does not match my experience.
The issue with some is that they never actually did set a budget. Obviously ndas prevent name calling…
I literally don’t know any AAA studio that doesn’t have upper limits regarding file size. It is even a requirement set by Sony and Microsoft as part of their validation process. Each DLC deployment even has costs depending on its file size.
Obviously true, but people/companies don’t always make games for consoles.
With a console you are actually sort of forced to have hard limits… Still, if you consider that a PS4 DLC can be 25GB for something one could equate to a character skin, that’s still rather ridiculous.
What I’m trying to say is that Once Upon A Time, when large hard drives were around 2GB people paid MUCH more attention to what they were doing.
Break down any N64 game for instance.
When 64MB is literally ALL you have, you got to get smart about stuff 
I have a better comparison to kind of put into perspective how over time companies are generally more lax in term of what you can do in a game and HDD space:
GTA San Andreas - 5.5 GB.
GTA V - 15GB
GTA5 - 65GB
Red Dead Redemption 2 - 150GB
Now do keep in mind that RDR2 is basically the holy grail of what games today SHOULD be, where GTA4/5 was only “OK” comparatively when GTA San Andreas actually offered a whole lot more then both 4 and 5 did for 1/3 of the size of 4…
Essentially RDR2 is the San Andreas of modern times (maybe less fun though, idk, I enjoyed it).
I this case for me and indie game developers, the better idea is create a small game that focus on same (mission,quests,tasks in game) Mostly this method use MMORPG games such as Black Desert.
Player should repeats missions and get better (rewards,level,item)
and instead build BIG world from A-Z point like Ubisoft, focus on small map, but it doesn’t mean that small map need to be a game with expanded story from A to Z point. You may create story ingame that takes a lot of time to finish mission from A-B point (for player) by adding impediment.
Example - you need to go outside from house becuase you’re in, and then you’re finish the game but before go outside add impediment that prolongs game, and it this case is a key to door that you’re looking for.
In results player or gamer will play this game much longer.