well their are a few others around, specifically their is [stonevox][1] which was made for stonehearth, though its a bit “unstable” if i’m not mistaken, though come to think of it, im not sure if it allows for multiple matrices.
but hey, its free so you might as well test it out.
[1]: StoneVox 3D - Community Voxel Modeler for StoneHearth