[Won't change] Sloped 3D Floor Missing Textures

[SPZ1]

I found this issue where the closest sloped 3D floor (in the attached demo .WAD) is missing its floor texture, then in the middle both textures are present, and at the end the ceiling texture is missing.

[Graf Zahl]

There is one important rule with 3D floors this map violates: No plane intersections! If planes intersect the renderer cannot deal with the outcome. Your entire setup only has 3D floors that do intersect with the floor and ceiling of the sector they are in.