RadED: Carmack's experimental voxel editor for Doom circa 1992

I was doing a totally unrelated Google search when I came across this video:

The video is quite hard to make out, but it's an editor for creating voxels that apparently John Carmack toyed with in between Wolf3D and Doom.

And what's more, we have source code for it (scroll to very bottom), mirror:

recent note: this may not all be correct anymore...  Look in the source
if you are curious.

RADED basic operation:

RADED holofile

The holograms are composed of 64 platters of 64 radial sections with
32 evenly spaced divisions.

Right clicking in the circular edit area will draw with the current edit
color. The projection will not be updated until the mouse button is released.

Left clicking in the edit area changes the edit color to the color clicked
on.

Pressing 'S' saves the current hologram.

Pressing 'C' while the cursor is in the edit window will draw a circle
with a radius out to the cursor.  Everything inside is erased.

Clicking in the color palette area changes the current edit color.

Clicking in the area between views selects the platters to write through.The
platter first clicked on is the one displayed, but you can drag the selected
area so that it covers multiple platters.  When multiple platters are
selected, drawing is done in all the platters at once.

The left/right arrow keys rotate the image.

The 1/2 keys rotate the projection without redrawing the edit window until
you release the key.

Clicking along the bottom of the screen rotate the image to a specific angle
based on the x position of the click.

The up/down arrow keys move the platter selection range up and down.

Note the exclusive references to "holograms", which makes me wonder if Carmack had never heard of voxels at that point and was sort of re-inventing the concept. Also note that the voxels are defined radially(!) instead of the more normal XYZ coordinates we generally think of today.

Anyways, maybe I am just totally out of the loop, but I had no idea that John Carmack had experimented with VOXEL ENEMIES before giving up and falling back to boring old vanilla sprites.

Linguica said:

Note the exclusive references to "holograms", which makes me wonder if Carmack had never heard of voxels at that point and was sort of re-inventing the concept.

Probably.

Linguica said:

Also note that the voxels are defined radially(!) instead of the more normal XYZ coordinates we generally think of today.

I'm not surprised, since he also used polar coordinates in some places in Doom where it would have been so much simpler to use Cartesian coordinates.

All those references to "holograms" and "holofiles"...was Carmack a Trekkie? O_o

Yes. He has stated in interviews before that TNG's holodeck was his main motivation for making games, especially ones that emulated reality more and more.

Wow!

The setup they were using was a silicon graphics indigo for map
editing, and a room full of custom hardware for the rendering.
The images were rendered on three monitors inside the cockpit at
640*480*24 bit color at 33 frames per second (weird).

Sounds familiar. The inspiration for Doom's three screen mode?

This is amazing. What's next? Fuzzy Pumper Palette Shop?

It just occurred to me that "voxel cylinders" would be relatively simple and quite efficient to render with a column-based renderer and various precalculated LUTs like the ones used in Doom, assuming that the top and bottom would be invisible (you would see no weird "flat top" if you were higher than such a model, but their "brim" would simply curve. After all, you only see 180 degrees of a cylinder's face at any time.

Different thicknesses/surface depths of such cylindrical models could easily be handled by drawing the innermost cores first -and it would also be simple to avoid needless overdraw- the model editor itself could reduce the models to "hollow shells", so basically you'd just be rendering a bunch of columns at different distances. A single voxel would be like a thin curved pixel hanging in the air -not like a cube, so not everything would look good in such a system. Maybe that's what Carmack had in mind? A voxel system that could be easily integrated in Doom's rendering engine, without having to add proper polygon/voxel support?

Great find! And seriously, whenever I think I can finally SORT OF understand the limits of Carmack's genius something new comes up. If computers hadn't been invented, Carmack would have built them himself.