Reaction-Diffusion Cube

thingiverse

My practice of reaction-diffusion model. The reaction-diffusion system is a model to generate pattern of surface of some animals (such as zebra or fish). Nice explanation here: http://www.karlsims.com/rd.html . Calculated cubic world with C program, place around cube with OpenSCAD program. Print Settings Printer: Da Vinci 2.0 Duo Rafts: Yes Supports: Yes Notes: To change reaction-diffusion pattern (various parameters of reaction-diffusion, random seed, resolution, # of iteration), edit "rdcube.c", compile and run, redirect output to "rddube-sub.scad". The algorithm is Gray-Scott model on cube world (each face is made with matrix, which continues at the edge with the next face). Currently the C program is too dirty (complex), and I don't upload. To change design of the cube, change "rdcube.scad". I made it to consist a manifold object, but OpenSCAD itself or other CAD software says it's not a manifold... (I don't know the reason.) I fixed it with Meshmixer, then Microsoft Model Repair service. The "rdcube-sub.scad" is a part of OpenSCAD program, which initializes array v[] with the data. I don't have texture mapping (zmap) skill/software to place matrix onto surface, so did this way. Please comment better ways. How I Designed This I used different three C programs (not shown here) to calculate reaction-diffusion system, which made output as OpenSCAD array v[] initializer sub program, then render with OpenSCAD. Calculation mesh is 40 x 40 for each face, object size is scaled to 40 x 40 x 40 mm. The world has no end like torus, but it's interesting that edges seems to have singularity, and the pattern aligns parallel/vertical to edges. The rdcube2 is made with smaller "diffusion rate" F, then calculate difference with smaller cube using Blender. The difference (outer pattern) is for black filament, inner cube for white filament, to print out with dual color 3D printer. On the rdcube3, the kill ratio k varies between one corner to opposite corner. Then calculate difference (outer, white) and union (inner, black) with smaller cube, print out with dual color.