Bruh, this is our terrain material limits? Whoa… ok umm yeah this prolly needs to be modernized, I never noticed because I always do my own shader for terrains because 3 diffuse textures is simply not enough plus I preferer triplanar sampling (and I usually make it parametrically paint itself).
To add emissive textures to this though oof, that would take a little bit of reworking because you would need to convert it to some sort of “material” struct that has an association between the diffuse and emissive textures plus any additional emissive arguments you might need.
The ambient Color would be ezpz but emissive would take quite a bit of reworking.
If we were going to dive back into the Terrain material, id argue we bite the full bullet and add 6 layer support that includes a possible emissive texture, triplanar sampling option, and a toggleable texture synthesis method to create infinite texture diversity.
There is also the mixMaterial (which is like the terrainMaterial) which supports up to 8 texture mixes. But same thing, no ambientColor and no emissiveColor (although the emissiveColor for a terrain wouldn’t be useful I think.)
8 would be good, but I worry if we add emissive to that as well then 16 texture buffers on a single shader is the limit and then nothing else would be supported (splat texture) hence why I said 6 layers.
Maybe I need to just clean up my best terrain shader and kick it over.