This is a simple libary for creating voxel 3D-obj files in python. There is another implementation in cpp (link: https://github.com/martinpflaum/voxel_obj_lib_in_cpp)
WorldGrid takes as first parameter the 3d grid size of the world. In our example the grid would be of size 4x4x4. The second parameter of WorldGrid is the size of the colorpallete. With a colorpallete of size 8, the textures you want to apply onto the object should be in a 8x8 grid. A 8x8 grid is for example 64x64 - each texture is then 8x8 pixel large. Its not that complicated just try some textures with same width and hight out.
In __setitem__ the first argument are the x,y,z coordinate of the cube you want to change. The second argument of __setitem__ is the colorvalue of the voxel. -1 stands for void. The colorvalue 0 corresponds to the pixel value at point 0,0 in texture palette. The obj() function returns the string that contains the objfile
from voxelobj import *
worldGrid = WorldGrid(4,8)
worldGrid[1,1,1] = 1
worldGrid[0,1,1] = -1
worldGrid[1,0,1] = -1
worldGrid[1,1,0] = -1
worldGrid[2,1,1] = -1
worldGrid[1,2,1] = -1
worldGrid[1,1,2] = -1
write("output.obj",worldGrid.obj())