Some materials in our Poliigon library are tagged with the "Game Ready" attribute, but what does this mean?
It simply means that the resolution sizes of these materials are set to powers of two, such as 1024, 2048, 4096 etc. They are not necessarily square though, as some may be 2048x1024 for example. Occasionally, you may find a "Game Ready" texture that has a resolution size that is not exactly set to a power of two size (ex. 4000 x 2000) though these textures can still be used for game engines when you resize them to a power of two resolution size (ex. resize 4000 x 2000 to 4096 x 2048).
Generally, artists do not have to pay much attention to these "Game Ready" resolution sizes as renderers for 3D Applications such as 3DS Max, Maya, Cinema 4D and Blender are not particularly fussy about which resolution sizes are used.
However, when dealing with a gaming engine, using a texture that is not "Game Ready" will have some fairly major drawbacks. Let's take Unity for example: When you use textures with resolutions that aren't power of two, they will be converted into an uncompressed RGBA 32bit format. This format will take up more GPU memory and load much slower when you compare it with the compressed DXT format that is used for power of two textures.
In short, if you're working in a gaming engine, be it Unity, UE4 or any other, be sure to use one of our "Game Ready" materials whenever possible. You can easily find them by searching our library for textures with the "Game Ready" tag. If for whatever reason you can't find the materials you're after with this "Game Ready" tag, you could search for textures without this tag and then manually resize the material in an image editor such as Photoshop or Gimp.
If you need any further advice or assistance with using our materials in a gaming engine, please contact us at firstname.lastname@example.org.