I'm still working on the terrain shader and painting tool. Smooth painting is now implemented, but needs some further improvements.

I also added distance LOD for detail maps. The detail maps fade out smoothly if the camera moves away. If they fully faded out, only the terrain's diffuse texture is visible. In my example screenshot below, I used a one-color diffuse texture to show this effect. But you can also use a low-res texture as diffuse map.