After painting down the texture, you can then use a brush to raise of lower the area but with so much more control than the current system. Creating very steep peaks or even vertical cliffs is totally possible and was one of the examples that Charles created in only a few seconds before I could even ask whether it was possible. He then switched out to another texture to give the cliff face a more earth-like look, and added a third grass texture with a different opacity to add patches. Opacity means controlling just how transparent something is, so being able to paint texture on top of texture with different levels of opacity gives you an insane level of control and is much how traditional painters create their work using paint on canvas. So for example you can first put down some ground texture at 100%, then some grass at 80% so that some of the ground shows through, and then maybe some rougher grass at 20% for patches here and there. So having totally deformable terrain with textures of ice and mud is very easy to do and there doesn't appear to be a set limit to the number of textures you can place over each other.