Splat textures and Heightmaps

(edit) reitterating my stupidity. The alphamap picture is composed of red, green, and blue segments which corresponde to the terrain in the coding using tex1, tex2, and tex3, to place textures, correct?

How was this created?

Secondly i’m just confused on the heightmap that uses mountains512.png, i notice the brighter the white, the higher the mountain, but i don’t understand how that was created.

Splat textures just never really made any sense to me.