Really, my work?
The interesting thing in my mind wasnt the renderer at all, it was the editing method that I was struggling to get together, took me ages and a gpu flood fill to get my voxel csg going really fast. (for operating on GIANT voxel sparse worlds - complicates the algorythm)
Hand editing millions and millions of voxels (with a csg engine) to make a world is like entering a million data pieces into the cyc database, it takes ages, and I ended up disbanding the project cause I didnt think hand editing was the way to make these voxel worlds, and procedural generation makes more sense.
Just think, a density function (a three dimension equation of matter of space) relates to voxel space without any conversion, so thats what I think the coolest way to make something "big" voxel wise would be.
Making voxel characters is easier, (and hand editing now actually makes more sense) and you can even store the voxels in a brute force lot of data, space and matter, if you were making characters, leave the world/environment to procedural generation, and actually use brute volume stores for the characters themselves, id imagine you could get to 2048x2048x2048 voxels??? (with the latest equipment, mind you) not bad..., doing it gpu wise is what id do.
If your just using brute force volume stores (in lots of textures) then your boolean comparisons to do csg are the easiest thing imaginable to code, just flip bits on and off and its that simple.
you convert to SVO after the modelling is complete and disc stored.
The really cool gpu voxel programs are the realtime liquid/smoke generators, they are the coolest thing i saw. They involve some kind of feedback loop on a finite volume. but im doing everything gpu of course.
Remember, theres no point having a voxel renderer with nothing to render with, so that was my main effort into voxels was for, modelling.
3d coat is a cool modeller, i recommend and also purchased the student license for. (and its a christian company, so its like buying a pass into heaven hehe)