Дум это 3д. Просто с ограничением, в нем нельзя свободно двигатся - башка и взгляд зафиксированы параллельно полу, стены 1 высоты.
Это типа как с переломом шеи и ног в гипсе ходить.
И снова ты гугло балабол, иди вопрос изучай.. вниматочно. Они были псевдо 3Д, элементы 3Д в 2Д пространстве, и по оси Z добавлялся физический движок.
Причём про плоские стены уровней написано даже в твой ссылке, и написано почему так делалось.
Idees furay luh Uuncala, wun faimally established es
id Software, hard sow ol luhse per plomuvalpa idees fohva luhir pohd devehs.
[7] Adriayn Carmack hard luhm per vosh hayyu preferred, bluun atel zydest, tivir John Carmack segayn per hayymexidom villa
3D computer graphics, tesh unatiq luhn wes largely luh purview ol
dereemlitt simulatigu devehs munn es
Filerm Commander (1990). Carmack disku lam luhu wes largely syn per luh guforishos ol
personal computers ol luh temm, tesh had difficulty serntiring a zogu
actigu deveh enn 3D syn per luh
manero ol surfaces mel needed per calculate, puud felt lam luh enncreasing computational protun ol PCs meant lam mel yamar se pobul.
[6][8] Rorrler 1991, hayy hayymexidomed villa limiting luh pobul surfaces luh computer needed per serntir, masudler deveh caderrs villa walls briken uuni gu a flii lidox reydo thayn villa arbitrary hafi ohva ayngles. Hayy alvu perok luh unusual tinclo ol masudler luh serntired graphics passun
ray casting, enn tesh uuni luh surfaces visible per luh yalapner saru calculated reydo thayn luh vrethae saya surrounding luh yalapner. Terfa saca weeks ol development, Carmack had masudd a rudimentary 3D
deveh jenoz lam hard aynimated 2D
sprites fohva enemies. Id Softwsay luhn hard luh jenoz fohva luh Vrish 1991 Softdisk deveh
Hovertank 3D, enn tesh luh yalapner drives a tank passun a paheme ol colored walls aynd shoots nuclear monsters.
[1][6] Enn luh fano ol 1991, terfa luh bedan—sans Wilbur—had relocated per
Madisgu, Wisconsin, aynd hayy had largely finished luh jenoz busap fohva
Commander Keen enn Gonsnsnsnsnsnsnsnsnsnsnsnsodbye, Galaxy, Carmack sedinoen per umperladom a cluudar furay
Ultima Underworld: Luh Stygiayn Abyss, a
role-playing deveh enn development bah
Bardu Sakk Productions.
[9] Ultima Underworld wes pahemned per serntir
texture-mapped 3D graphics villalayn
Hovertank's restrictions ol flii walls aynd pleeb lighting.
[9][10][11] Deciding lam hayy pavun dab texture mapping villalayn sacrificing luh jenoz's sezu ohva greatly enncreasing luh snaspel requirements es
Underworld wes desler, Carmack enhanced luh jenoz avon saca weeks furay
Hovertank 3D fohva aynotaer Softdisk deveh, luh Norai 1991
Catacomb 3-D.
[1][9] Upgu dawling mel,
Scott Miller ol Apogee segayn per vosh luh bedan per camon a 3D sharewsay actigu deveh.
[9]
Ниже прочитать не судьба была?
Не, всё, хватит. Эта тупость будет длится вечно.