Basically you start a new map, draw sector(s) in the shape that you want your 3d floor(s) to look like from the "front". Then run the script and it takes that XY drawing and flips it up to XZ and extrudes it into the Y axis and saves it as a 3d floor. You can then copy and paste that into your working map.
So for example you could draw a ring and have it extruded into a pipe:
Spoiler:Or draw the DOOM logo:
Spoiler:It applies the same textures that you drew the original sector with, and also uses the light level to set the opacity of the 3d floor, but I've notice that only seems to work on flat floors with no slopes, so I don't know how useful that is. Also that software mode can only see flat floors, but collision detection does still work even if you can't see them.
Anyway, is that useful for anyone? It's just a stand-alone script, I wrote it in PowerShell. But maybe if there's some interest in it I could slap an interface on it or put it as a plug-in for UDB or something?
EDIT: My script is posted here.
Here is the latest download link: 3dFloors_Extrude.zip
Important file in the package:
3dFloors_Extrude.ps1 - The main script file
3dFloors_Extrude.cfg - The configuration settings file
3dFloors_Extrude.txt - The readme file. Have a look at this if this is your first time using this script.
Last updated 2022/01/18
The script now handles 2-sided lines properly, and I fixed the texturing. I fixed and tweaked a bunch of small things, and added better error handling.
The control sectors are marked not to show on the textured automap and the lines are set not to show on the regular automap. Thanks Enjay for the suggestion.
The lightlevel property no longer controls floor translucency, I moved than functionality over to the flooralpha property.