generate octet truss array with varying member radius, and generate a part based on a variable density solution from ToPy

octet_volfrac_array.py

# 
# http://www.variousconsequences.com/2012/12/octet-truss-for-topology-optimization.html 
# 
import scipy as sp 
import cPickle 
import octet 

if __name__ == "__main__":

    import os 

    # Path to the mged executables: 
    MGED_PATH = "~/brlcad/.build/bin/"

    r = sp.linspace(0.4, 1.545, 11)
    length = 8.0 
    unit = sp.sqrt(8.0**2 + 8.0**2) 
    parts = ""
    array_u = "r array"
    for i,ri in enumerate(r):
        parts = parts + octet.octet_prim("op%s"%i, sp.array([i*sp.sqrt(length**2 + length**2),0,0]), length, ri).mged_string()
        array_u = array_u + " u " + "op%s"%i
    array_u = array_u + "\n" 


    fout = open("array.mged","w")
    fout.write(parts)
    fout.write(array_u) 
    fout.close()

#
# this takes too much memory
#
    # fin = open("desvars.pkl","r") 
    # dogleg = cPickle.load(fin) 
    # fin.close()
    # fin = open("volfrac_poly.pkl","r")
    # pvf = cPickle.load(fin)
    # fin.close()
    # parts = ""
    # dogleg_u = "r dogleg"
    # ni,nj,nk = dogleg.shape
    # r = sp.zeros(dogleg.shape)
    # count = -1 
    # # for i,di in enumerate(dogleg):
    # for i in xrange(ni):
    #     for j in xrange(nj):
    #         for k in xrange(nk): 
    #             count = count + 1 
    #             if dogleg[i,j,k] == dogleg.min(): # void 
    #                 pass
    #             else:
    #                 if dogleg[i,j,k] == 1.0: # solid cube
    #                     parts = parts + "in op%s rpp %g %g %g %g %g %g\n"%(count,i*unit,i*unit+unit,j*unit,j*unit+unit,k*unit,k*unit+unit)
    #                 else: # octet truss for intermediate densities 
    #                     r[i,j,k] = sp.polyval(pvf, dogleg[i,j,k]) 
    #                     parts = parts + octet.octet_prim("op%s"%count, sp.array([i*unit,j*unit,k*unit]), length, r[i,j,k]).mged_string()
    #                 dogleg_u = dogleg_u + " u " + "op%s"%count
    # fout = open("dogleg.mged","w")
    # fout.write(parts)
    # fout.write(dogleg_u)
    # fout.close()