This was quite a challenge as I made a point of not using any photo textures. I built the texture up in layers, using the uvs and the ambient occlusion from mudbos as a point of reference.
I started with a general grey, using textures brushes to get a little variance in tone. This seemed too dark, so I lightened it up and added some colour variance, adding some green patches with a stiple sort of brush.
I then added the AO map in. After looking at some pictures of granite I saw that white splotches are common so I added this in.
I then added some grass and moss, in a bright dark green. To make this I used another stipple brush in a dark green and then added a lighter one on top. I then went in with the lighter colour and added some grass like lines.
I then added some white dots and lines to give a little fantasy style twist.
I then upped the constrast on the grey background and added in some more tone.
It looked pretty good on the stones but there was something missing that I couldn’t put my finger on. The issue was that moss generally only grows on one side. I then tried this, but actually thought the other one was better.
Combining them looked pretty good, as it made it look less like one rock model.