3D Tools ain't generally cheap.
Generally you would sculpt details that would later become a normal map for a base mesh. With something like ZBrush you can generate your low poly base mesh and convert the details to a normal map. What you'll be looking for in your models is to have a low/mid poly base mesh with a texture map and a normal map to simulate the high details of your high polygon mesh.
There are programs that offer sculpting, I know Hexagon 2 has a sculpter, which is okay, iirc it exports greyscale bump maps, which can be converted to normal maps if you've got the tools to do it. Hexagon 2 is still free and you can model your base mesh in there too. I used to have stability problems with it and I don't get a great performance on my Intel GMA card, but then it's a GMA
, however, these days it's pretty stable.
So you can model, sculpt UV map and texture all in the same editor. I can write up a tutorial to explain how to do it. I've already got a tutorial on how to create your first textured 3D model in Hexagon, here
. So I can write up and show you the sculting tools.
If you're willing to pay money, there is Silo 2
, which follows the same principle as Hexagon, but in my opinion it's a far superior tool and has more features (for example, it has a retoplogy tool)
If you're not quite willing to go as far as ZBrush's hefty price tag, there's also 3D Coat
, which I think is a pretty cool tool, not as great as ZBrush, but exists as a cheaper alternative.
I will post up my Hexagon 2 scultping tut once it's done.