Hey all. Early on in my UE5 experience, dealing with 4k materials, I adopted a practice of saving/converting textures to jpg. From what I gather on the internet, this is a much hated practice, because it “adds to the artifacts” already created when UE converts the images to DXT5 for rendering. It’s useless, too, apparently, because all textures in a game get re-compressed in the eventual game package anyway. I have just 2 problems with this though.
- Not everyone is a developer at a game studio on a machine with infinite storage space. I reckon I’m not alone in that I want to store more high quality assets DURING DEVELOPMENT without unreal projects taking over my whole machine. High quality JPGs store at about 1/4 the size of TGA, and 1/8 the size of quixel’s 32 bit .exr format.
- I’ve run the tests over and over. I simply cannot find any significant visual difference between TGA/exr vs high quality quality JPG files converted from these. Where are these horrible artifacts everyone’s talking about?
Here’s an example. This “pattered pavers” 4k material from quixel is a total of 128mb between the albedo and normal textures. Here’s a side by side comparison of what it looks like (in the engine) before and after I’ve converted those textures from .exr to a jpg in photoshop, reducing the total size to just 16mb.
tex_test_pavers_original.bmp (1.9 MB)
tex_test_pavers_jpg.bmp (1.9 MB)
Go ahead, open them up in an image program and lay them over each other. You may notice a VERY sight granularity difference when zoomed in, but essentially, they look identical. And yes, I’ve tried lit, unlit, and various angles of shading to test the normal map, as well as many other textures. So, what do you think - are the 112 extra mb worth it? I must be missing something. Maybe it’s not so good for sharp lined textures, like in more “cartoon” style games? If I’m right, I would really love it if quixel, or everyone for that matter, would just start allowing me to download content in jpg format. That would be really useful to people with slower internet connections or who have limited hard drive space.
By the way, if anyone else is interested in doing this, I can explain further how. There is a trick to converting the normal maps, and a couple other little details to be aware of.