How to make tillable materials in Substance designer to limit draw-calls in UE4

skyboyfly

So I'm just curious how I can create something like Uncharted 4 did, in which they would create only a few material bases in substance designer, and tile things onto it in the node editor, heavily/intensivly reducing drawcalls when exporting into UE4, but making there look like there was hundreds/thousands of different materials.

what would you officially call the term for this, and is there any video tuts on how to do this.

leleuxart

This isn't something strictly related to UE4. What you're thinking of is probably what DDO and Painter do. You make a large selection of individual tiling materials, like bare metal, paint, rust, dirt, etc., then composite them together in one of the aforementioned programs on your asset. The said program would then export out a single Diffuse, Normal, Roughness, etc. That's the common workflow now. 

There is another option available in UE4 that isn't too performance friendly. Layered Materials basically do what DDO/Painter do, but inside the shader. It requires the masks that you'd make in DDO/Painter to be imported into UE4, where you'd blend between two materials based on the masks. For each material, you'd import the textures and make a Material Function(which is used as a Material Layer).There is no compositing unless you do one of the LOD options in UE4(I forgot the name), but it's pretty janky and you lose resolution after it merges them all into a single texture. You'd be better off doing it manually in DDO/Painter if you want a single texture but good resolution.

m4dcow

You could also use vertex blended materials (though in Uncharted 4, they are able to use multiple vertex colour channels, UE4 supports 1 RGBA AFAIK). They do all sorts of different stuff with UV channels to mix up the blending too.

I'm on my phone and can't search for the UC4 thread where they answered questions.

As far as substance designer you would make your textures including heightmaps, and blend them in the material editor in UE4 using vertex colours.