A macro texture is any texture that has the texture coordinate tiling set to be a larger scale than the base textures. Used to break up tiling artifacts when textures are mapped to huge flat surfaces.
Usually you would use a very random number ( one that doesn’t divide evenly with the base coordinates) so that you don’t get matching patterns every few base texture repeats.
In the starter content, many of the materials use the macro texture to vary the roughness. They use the same texture at three different scales blended together each with varying scale to try and capture a sort of near, mid, far and ultra far back tiling. Sometimes we use the cameradepthfade material function to control the dominance of the various macros, other times a simple even blend works. There is really no rule as to how to use them. Some materials use macro normal maps , macro diffuse stains etc.
For every different type of macro texture you should try and use unique scales to further break up the repeating patterns.
As your post hints at, the term “macro texture” is itself relative especially with regard to modern material techniques. It is not uncommon for every texture inside of a material to have a unique scale except for a black and white unique mask. In general macro refers to the more low frequency detail.
In some of the unreal project materials i see a comment box talking about macro textures…what exactly are they? what are they doing? and how do I learn to use them??
Macro textures help you get more detail and variation in your materials, and they are used in addition to your base roughness/metallic/diffuse maps. There isn’t much to learn about them as you may or may not need so much detail depending on your material. But as an example; if you want to have a realistic, rusty iron then you’ll use a mask for the rusty areas, and then use that mask again to Lerp between two macro textures(detail masks) and increase the tiling of those macros to get finer wear and tear looks.
Ok. I kinda see. I saw that it looked like some of the textures never repeat. And I really enjoyed that…I guess that’s look I was going for for a rocky type of ground material.
Thanks guys.
Anybody can make a macro normal. They are just like any other normal map. The only difference is they tend to have smoother details so that they look good when scaled way up. You could try making heightmaps from photoshop clouds and converting those to normal maps.
