Hello Everyone!
Just a quick question, I’m in the process of developing my first game, I had always used JPEGs as my general file format for Textures.
Does this matter? What is the most optimised (best) file format to use in UE4?
Thanks for any help!
Mike
.jpg isnt the way to go, as it already has compression.
Combine with with ue4’s own compression and you will end up with images that are compressed twice.
The best file format is .png, but that cant contain alpha.
In that case .tga (32 bit) will work if you need alpha’s.
If you want to go all out though, .psd also works 
Do you know which format is the most efficiently rendered? Or are they all rendered in the same way?
They will be compressed to an internal file type anyways, so the best way to go is as compressionless as possible. In that case .PNG is probably the best as I said before, unless you really need an alpha, then TGA is great.
Thanks so much for the help! I appreciate it!
i have been using .png textures with alpha channels, and they work just fine in ue4.
Then you gotta show your workflow, because .PNG and alpha is messed up, especially if the alpha has nothing to do with the image itself. (i.e. 4 cloud textures in rgba)
So if you have a way to make alpha in png always work, I’d really like to know
.PNG alphas work fine, its photoshop’s PNG exporter that seems to be your problem. i use Gimp instead of photoshop, and it exports transparent PNGs without any special workflow, and they import into ue4 without any problems.
try importing this into UE4, it should work fine:
Huh?? isn’t it the other way round? PNGs are the best for alphas and TGAs are for regular images?
Nope, PNGs have a lot of issues with alpha and 16 bit PNGs, not necessarily an issue with the format itself, but how different applications work with it.
I use PNGs for anything without alpha, and TGA for anything with alpha.
same!
This message saved me after hours spend on trying to figure out why my png image kept getting cropped when exporting from Photoshop. I downloaded Gimp and on export you have so many glorious options compared to Photoshop, there is literally a checkbox called “Save color values from transparent pixels.”
I was trying to do edits on an ORME map with emission data stored in the alpha value, but it kept cropping the transparent pixels no matter what export settings I chose. I even tried .tga, but that just cropped individual islands instead, so that was even worse.
Cheers man, your post from 2016 saved me!
