Jaakko Saari shared a wonderful little plugin, which will help you conquer heightmap for rocky materials.
Good rocks are like money or good health. You can’t get enough of them. Making rocks just got a little easier, thanks to the wonderful work by Jaakko Saari. He uploaded a free heightmap generator for Substance Designer. Both .sbs and .sbsar files are included.
It gives you easy controls for creation of variety of rock shapes instantly. You could blend them together for more advanced things materials. It’s a wonderful tool, which can quickly help you build amazing rock materials.