maybe interesting for you... It is possible to load .obj meshes into MagicalVoxel,
when converting .obj to .off and then use these two converters* from here:
or even if you want only render you have the free Simlab Composer Lite (works with any 3D format files! :)
who has a Voxel function! :) (Maxi 1920*1040) (you can only save in proprietary format! )
The idea is that you can take any .obj convert it and load into Magical Voxel,
so that you don't have to model it in there... :-) Or to simply voxelize and
color a converted .obj file.
O.k. according to a Twitter post, i can drag and drop an .obj file or image
to the canvas, but the resolution is then for the .obj much smaller than
how i did it with the converters...
So the best worflow is import OBJ to Magica Voxel (very speedy) then use the Simlab Lite for a more elaborated rendering!
(because the Simlab Voxelisation directly (some posts above) is some painful - i discourage that! )
MeshMixer or Rocket3F MeshLab or your favorite 3D Package for the OBJ repair...
I just thought to mention that ZBrush can also convert meshes to a voxelized representation.
Use Tool ➔ Subtool ➔ Remesh All, or Tool ➔ Unified Skin to voxelize meshes. Turn down Polish / Smooth to 0. Remesh All has more options, and creates a new subtool, while Unified Skin creates a new tool you have to activate.