You Want Sloped 3D Floors In Your Maps?

To make sloped 3D floors it is assumed you’ve worked with both slopes, and with 3D floors before. If not, you can learn some more about slopes from my tutorial here, and you can read about 3D floors here.

To start, lets create a 3D floor and position it where you would like it to be, but without any sloping. To make the 3D floor, tag the sector the 3D floor is supposed to be in; then create a dummy sector ‘outside’ of the map. Next, select one of the linedefs fo the dummy sector, and give it the line action 160 (Sector_Set3dFloor), define the tag and then leave the remaining paramters as their defaults.

In this example we’re going to make a sloped section to this archway. As you can see in the below image, I’ve created a ‘box’ where I want this sloped section to be, in line with the part it’s connecting to.

Dummy Sector Positioning Is Crucial!

So here’s the part that usually trips everyone up – the dummy sector for a sloped 3D floor must be parallel to where the slope will be in the map itself. To try and explain this better, imagine we are ‘projecting’ the 3D slope. The illustration below should help clarify what I mean!

So now you have your dummy sector for the 3D floor lined up, it’s time to add an additional dummy sector which is connected to it, and then create a slope here. Apply linedef action 181 (Plane_Align) to the line that connects these two sectors, and configure it so that the 3D floor’s dummy sector is now sloped. This should then be translated to in the map itself. Adjust the heights of both of these dummy sectors until you have a slope that looks like you expect!

Closing Comments

There you have it – beautiful sloped 3D floors in your level! You now have the theoretical power to craft anything you want in Doom, as long as you have the patience. Do keep in mind that for each 3D floor you add, you’re causing the engine more strain.

Also keep in mind that specifically sloped 3D floors do not render in software renderers (at the time of writing. It was once the case that 3D floors didn’t render in software modes at all).

Lastly, another useful / interesting feature to note is that the sloped 3D floor can continue far beyond what the dummy sector’s size is, so if you were to tag a sector which is much larger than the dummy sector, you will see the sloped 3D floor continue on beyond using the same angle etc. If this tutorial helped you or could be of use to a friend, please share it!