Layer Blend Options

[Edebran]

@rhino_punch_brg

There’s a great tutorial/write-up here: WorldMachine + UE4: Full Workflow

In short:
**1) Weight Blend **ensures you have some value (0-1) for each material. As you paint more value of one material, it reduces the underlying materials. This is usually the most common blend mode.
**2) Height Blend **utilizes a height mask (sometimes stored in the Alpha channel of your baseColor map) to blend materials. This ensures that details defined by the white portions of your height mask show through other layers. For example, think something like rocks or dirt mounds popping through say a grass or sand layer.
**3) Alpha Blend **TBH, isn’t used all that often on multiple layers. Typically though, it’s used for your base layer. In your layer setup, set your base layer to “LB Alpha Blend” and it’s preview weight set to 1.0. This ensures that any black spots are removed when other layers are set to Height Blend.

From the UE4 Documentation, The image on the left is what happens when you use only Height Blend. Notice the black spots. Setting your base layer to Alpha Blend and preview weight of 1.0 makes sure those spots aren’t visible.

Instead of creating Layer Blend nodes for each channel (baseColor, Roughness, Normals, etc) use a “MakeMaterialAttributes” node for each of your layers, connect their outputs to a singe Layer Blend node, and finally connect it’s output to your main material. Note: in the material output node, you’ll need to change it to “Use Material Attributes”.

And finally, to tile your materials on the landscape, just setup something similar to this and you’ll get all the control you need. Note: in my example, I’m using the exact same textures for the near and far baseColor as well as the near and far Normals. There’s no need for two separate textures; it’s a waste of resources. Note: The “Alpha” node of the Lerps is connect to the output of the distance blend Clamp node as shown in image 2.

I’m using the setup in that tutorial as well. Thanks to your input here I see some things that I could do better.