A set of texture-less low poly rocks created in Blender. Created loosely following the tutorial in this article http://adaptivesamples.com/2013/09/20/procedural-stylized-rock-modeling/ by Greg Zaal. Extra steps I took were manually defining edge areas by hand for each rock. And I also added a re-mesh modifier at the end. A little too low in detail for what I'm looking for, but was an interesting exercise in Blender nonetheless. If you're interested, I have left a hidden object with the modifiers I used in the .blend file. Duplicate it, move it around until your happy with the shape. Apply the modifiers. Add a Edge split modifier and set smooth shading. Then just edge-select areas in edit mode and mark sharp if the object is not already defined enough. To get different shapes such as the tall or flat rocks scale the object on the z-axis and play around with the sliders on displace and decimate modifiers.