Tire tracks in snow with Cinema 4D

I have found a nice free brush for photoshop to create tire tracks and footprints on a surface.
You create a black and white landscape image that you import in the displacement channel of your
material in Cinema 4D.
Get the "Displacement Brushes" at Downloads here -> www.blenderguru.com/tutorials/…
It come from blenderguru who explain how to draw the image.
You can also use your own hdr image for the background of your scene. This time you import
your hdr image in the Luminance channel.