Reality Factory

A quick technique for moddelling a simple rock for terrain.
Starting with a box vertex editing.

Turning some edges to a shape for extruding later.

Face extrude or bevel.

Editing/selecting faces on the other side for extruding.

Apply a Smoothing group rock,and uvw mapping.

Apply planar mapping to faces according their angle and then stich/ them together in the mapping window:center part with the bottom,center with right,right with back,etc.
Then if you want,make a high res version as a refference for creating a normal map.
Copy the stone,leave it the same place and hide the original.

Subdivide the mesh to use it for making a normal bump map,according the original low poly rock
in a utility program-or whatever tool you have for normal mapping.

Displacing the high poly with a map,for changing the general shape a little.

Adding a second displace with cells or cracks.

Apply a third displace for small dents using another noise map.

On the back it looks like this.The maps used for displace were procedural maps.
After done with the displace,you adjust the low poly vertexes to fit as possible with the high poly-which has changed shape after the displace.
The low poly model should be slightly smaller so it can fit in all the high poly details.

You then use the normal bump to the low poly model.

The comparison with the high poly-they are not exactly the same shape,but are close.
Before,and after the dot3 normal bump mapping:

I used 128-128 size diffuse for the actor file size and wont have much detail.
I attached the actor and .apj project sample anyway.
The rock and maps was made in a few hours,
and if you have more time and extrude more faces it could be better.

82 faces is not enough i d say and,fortunately the stencil shadow improved it a little.
You dont have to necessary use bumps if you can apply smooth the sharp angles a little (like the smaller rock).

Some 3d modelers have meshsmooth (it messes the uvw a little).