This is called New Rocks because I started a thread about four years back about this general angle. I've removed the tgd from that one though.
Here's a couple of graphs which create rocks. They are quite mushroomed. That is just a feature of these particular graphs. In Rocks 7.0, it's Rock profile that will adjust that and the blend start and end also have effect on how the rocks surface blends in. The overhang form is controlled in the colour tab of a fractal. In Rocks 6.0 it's Low High profile that mushrooms them. The rock "stems" surface fractal has no displacement. This would break at the join to the ground.
I may work out a way of linking the Grow and Low High profile in Rocks 6.0 because those things would be better linked. It just needs to be done a certain way. "Growing" the rocks isn't as good as I'd like.
There are both completely different. I could make lots of variations. The way I build these all depends on the outcome I want. If I don't need it to have a certain feature I don't built that in. Various power functions hooked in at different places can alter the rock shapes. that's just a matter of the shape you want.
The names on the adjusters may not be entirely logical. Rocks 7.0 has "Strength". that's a power which tends to puff the rock out before clamping.
Some adjustments will break the graphs. Watch for that. Breaks in displacement blend will occur but these graphs are not fool proof shaders that can be used any old way. To explain where breaks may occur would take some time. Just watch for it. Don't apply displacement to the "stems" on Rocks 6.0 for example. Some settings will wildy change the effect of others. I don't know that the settings I have made are the safest to start with in this respect.
Rocks 6.0 can be clumped in their distribution. Rocks 7.0 doesn't have that. Rocks 7.0 is just not as integrated into a scene the way the Rocks 6.0 is but Rocks 6.0 is perlin based so needs a bit more control of it's distribution.
In general, Rocks 6.0 should be kept small (probably smaller than I have made them here). Rocks 7.0 tends to work better for increasing the rocks to much larger scale or taller. Rocks 7.0 can be more like rocks sitting on small hills of the surrounding surface, maybe eroded at their base. This all depends on how you tweak them. In general, l use Rocks 7.0 (or variants of it - some less mushroom effect) if I want larger rocks that don't mask off perfectly with the surrounding ground like the fake stones do. I may add other variants.
Rocks 7.0 general type of form (voronoi based) can also have another feature built in which I haven't done yet that would allow you to have rocks of variation in surface i.e. one rock has a colour and displacement of one surface fractal and another a different surface and lots inbetween. Like the way you can have colour variation on the fake stones. That requires the graph to get bigger though. I will also be building in a way to distribute the rocks more unevenly in a similar fashion to fake stones. Using a seperate fractal to laterally displace Rocks 7.0 seems to be quite cool. This is what makes them good for bigger rocks.