Create grass field in Unreal Engine

We will add color variation slider to our material instance, which will let us to quickly change grass tint. First, we create Grass Master material (2-sided, masked material) and load our textures, starting from Albedo. Then we add SpeedTreeColorVariation node. We add scalar parameter "Color Variation" to it, so we can give each instance of grass small color variation.

To adjust the intensity of normal, we are separating blue channel, substract a value from it, then re-combine the result into RGB node and multiply with our Normal texture. If we create material instance, we will be able to change normal intensity and color variation by just moving the sliders.