3ds Max Rock Creation Kit
This package contains a 3ds Max scene with procedural models of various rocks. There are different sizes with complete construction history and used maps allowing any changes to the models like scaling, shape changing and other tweking that you would need.
This is not a usual model collection, this one gives you all the possibilities to study and use the technique that was used to create it from scratch. There was no sculpting involved and you can easily make more and more variations of the rocks without the need to sculp anything. All inside 3ds Max with basic tools.
The models are quite a dense geometry so keep in mind that you can quickly get to milions of polygons when you scatter them around your scene. This can be very resource hungry but it also enables you to render it in close up and you still get decent details.
The usage of this is endless. You can use the models as they are, just put them into your visualization and render. Or you can take the as a base for your own models that you create from these ones, it's all up to you how you use it.
Scene is prepared for V-Ray renderer and contains also the final shader for the rock as you can see on the renders below.
You will need 3ds Max 2012 or higher to open the scene.
Here's a sample model made with this kit so you can se the final quality: http://www.cgtrader.com/3d-models/architectural-exterior/landscape/rock-model-realistic-hi-poly