Gridtree x-1.0: Gnarl

I recently discovered an out-of-developement, but pretty cool 3d iterative rendering software called [Structure Synth](http://structuresynth.sourceforge.net). It's pretty primitive as far as capabilities go (cubes, spheres, lines, and triangles), but the expressive power of the language it's written in is phenomenal, and I've had fun experimenting "Gridtree" works by rendering a 90 degree arcs (which optionally tapers some amount) and then at the end of each arc randomly picks one of the following options for the next arc: * Curve the same direction * Curve left * Curve right * Curve back * Create *two* new arcs, each picked randomly from the previous four choices "Gnarl" has a tapering coefficient of -1, so instead of of forming arcs, the cubes fold in on each other in one spot. Not really in the same class as the other Gridtree forms, but still pretty neat.