How to create smooth curvy pathways

• We're looking to create a pathway like this.

• There are two ways of doing this: with texture blending, and with geometry.

• As the name suggests, texture blending is the blending of two textures so that one goes over the other and the two smoothly transition to each other. Texture blending is explained here. Once you get that done, just paint the shape of a pathway on the ground.

• Using geometry can be simple. Simply raise up the blocky version of your pathway, and curve the edges. You don't have to raise up the path that much, just enough to show it. Using 3D grass can add to the effect.