If you’re using a third party software to create your terrain height maps, like World Creator 2 or World Machine then you’re most likely familiar with splat or heat maps which separate different aspects of the terrain texturing set up.
To use your own Splat Map texture with M4, it’s a very similar process to using M4 to bake a splat texture in engine, with only one step added. First it’s best to familiarize yourself with baking textures with M4 before proceeding, you can find a how-to on it here.
Once you’re cool with that, lets get started.
After the baked version of the material has been applied to the terrain (Step 3 of the Splat / Heat Map Baker), click on your terrain and find the “Terrain Material” section within the details panel. Now click on the Magnifying Glass Icon, which will locate the Material Instance your terrain is using within the Content Browser. Open the Material Instance by double clicking it.
Once you have the Landscape’s Baked Material Instance open, scroll down to a section called “2a. Splatmap & Auto Mask Settings”. There you’ll find the Full Landscape Splatmap Texture which is applied to your terrain, go ahead and replace it with the one you’ve exported from your other terrain creation software.
The color legend for this is very important, as different colors correspond to different areas, or texturing of the map. It’s best to configure your third party software to fit these coloring conventions.
Green = Foothill Texturing
Blue = Cliff Texturing
Black = Flatlands as a whole
Red = Beach/Sand Texturing
In the future I’ll be expanding on this parameter set up to offer the Alpha channel as one more variation selection – most likely as the Mountain Top Region.