What texture file format do you use for game engines?

melviso

Does anyone know what file format is best for game engines preferably Unreal engine 4 with the best resolution and manageable file size? I am guessing .tiff or psd files will be too large. Probably have a master psd file and export textures as .jpeg or pngs as saving from the master psd file over the png each time will avoid compression. Can anyone share what format they use and why when importing textures into ue4.

I am currently revisting UE4 for archviz work

AtticusMars

I use TGA but I don't think it really makes any difference because UE4 will convert everything to a DXT compressed texture.

Kyetja

We generally use TGA when exporting, anyway, I recommend you check out this thread: http://polycount.com/discussion/112149/png-or-tga-i-dont-get-it/p1

melviso

Thanks for the replies.
@Kyetja Interesting read. TGA it is then. I did read somewhere about psd files being used with ue4. Isn't that going to be larger file size especially if it contains layers?

Kyetja

As AtticusMars mentioned above UE4 will turn them into it's a different file format anyway, so I don't think it would make a massive difference unless you to for example commit your textures to a Git, then having a bulky texture would be a disadvantage.
In my opinion using PNG or TGA is simply the best practice, with TGA having the added advantage of proper Alpha channels, and being more of an industry standard as far as I've noticed.

Eric Chadwick

PSD is easier to work in, layer support, groups, etc. But yes they make very large files, which can slow things down in a game engine when it is frequently re-converting them into usable assets. 

Another reason not to use PSDs directly is if you author multiple textures in one PSD. Albedo, Roughness, Normal, etc. You'll want to strip those out into individual TGAs. We have links to several tools to automate that process, see http://wiki.polycount.com/wiki/PhotoshopTools#Export_Tools

At work we have a separate SVN source control repository for PSDs and other source-art game assets, like Zbrush files, concept art, etc. This saves all the non-artists from syncing a large database of files they never use directly. The rest of the team only has to grab the considerably-smaller TGAs which are actually loaded by the game engine at runtime. Those TGAs also help at build time, because it makes different texture compressions for different targets, iOS vs. Android, etc.

ZacD

PNG is perfectly fine for RGB textures, but I would avoid it if you are using an alpha channel.

melviso

Okay, I will use TGA then. Will use a master PSD file and export in .tga format to the engine. I am using qsave with Photoshop.
Thanks for the info, guys.