How To Create Terrain Layers From Quixel Megascans Or Any Other PBR Textures/Materials
Here you go:
First of all, a terrain layer is a built-in Unity asset which is used on terrain as materials for texture painting and blend on terrain surface. To create a terrain layer file in Unity follow these links:
https://docs.unity3d.com/Manual/class-TerrainLayer.html
https://learn.unity.com/tutorial/texturize-terrains-with-materials
Regarding the Mask Map slot in terrain layer which is the key part in PBR workflow rendering, read the following:
If you look at the above picture, you will see that each channel in the mask holds specific data as follows:
- R = Metallic
- G = Ambient Occlusion
- B = Height
- A = Smoothness
Look for TerraWorld included terrain layers in the realistic templates which also have Mask Maps in their terrain layers so that TerraFormer (TerraWorld's terrain shader) can use these map types and data for high-end rendering of surface.
For example, when you turn on Tessellation in the TERRAIN tab, if terrain layer has heightmap data in its B channel of Mask Map in terrain layer, it will displace the terrain surface based on that data.
So you can use any PBR materials on terrain including MegaScans materials/textures or if found online and feed them into Mask Maps' channels so that you can make a mask out of them to use in TerraWorld layers.
The way we make maskmaps in TerraWorld to include channels in the mask map from single map files is by this handy tool on GitHub: https://github.com/andydbc/unity-texture-packer
Note: Unity's built-in terrain rendering does not take Mask Map into account for rendering and it only uses Diffuse and Normal Map textures for legacy rendering but if you use TerraFormer on your terrain, then it will handle a full PBR workflow using Mask Map's data. Watch this tutorial regarding TerraFormer to get started:
Also this video on TerraFormer (TerraWorld's advanced terrain shader)