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..::stone structure::..

Modelling this type of structure can be quite simple. Initially, you need to think about how this structure is built; how big each block is (etc) as we are going to have to build the thing like a brickie if it is to look as natural as possible. A simple tower formation is quite easy; starting off with a Tube primitive, a section of this can be extracted, holes capped and all hard edges chamfered so it appears like it was hand carved. Next it is a simple case of instance-rotating this “brick” around its own pivot point to create the desired formation. If your structure is more complex, try modelling it out as normal, then slicing it into chunks, capping holes and chamfering the sliced edges.

Next, create a number of procedural materials to simulate the type of rock you need; I’ve gone for a sandstone effect which is constructed using a number of nested turbulent Noise maps of reducing size used in multiple material slots (see screenshot) to add detail, plus a self illuminated falloff to create a dusty edge. This material was duplicated multiple times with its Noise map’s offset tweaked resulting in a unique texture, and its Diffuse Levels amended so we have multiple variations of material brightness. These materials now need to be randomly assigned to all the blocks in the scene… which is painstakingly tedious, it breaks up any repetitions that will be apparent in the render; scour the net for a script to do the random assignment in a single click!

Next, you’ll want to tweak the block placement a little to suggest there has been some subsidence over time. Randomly select a number of blocks in the Selection floater and offset them outwards using Local transformation; this should work provided your local axis hasn’t gone haywire or you have arranged the blocks with varying rotational values. If their local axes are all pointing outwards, you should be fine; if not, you may have to select groups of them and tweak their positions accordingly. Next, perform the same random selection and this time move them in slightly so you end up with a more natural layout.

Enlarge Screenshot The modelling of each block is exceptionally basic, but ensure to chamfer any hard edges. You may want to create a few versions of the same block with additional modelled detail.
Enlarge Screenshot The final formation with a number of blocks fallen to the ground courtesy of a quick Reactor simulation, with 11 different versions of the material randomly added.
Download the max file! Zip file to accompany.

..::Quick Tip::..

For additional realism, try scattering fragment particles over the blocks to simulate years of accumulated dust and debris. This will break up any remaining uniformity.

Initially published: 3D World magazine, Issue 93, August 2007.

Copyright Pete Draper, August 2007. Reproduction without permission prohibited.