# Chasm: The Rift

*Poor man's Quake.*

TODO

{ TODO: do more research about the engine, attempt to translate the Russian YT video. ~drummyfish }

**The engine** is possibly the most [interesting](interesting.md) part of the game as it used a combination of ["2.5D"](pseudo3d.md) level rendering and "true 3D" polygonal models for things like level decorations, enemies and weapon view model. Not much is known about the internals as the whole code is proprietary and "closed source", we may only inspect it visually and through [reverse engineering](reverse_engineering.md). To us it is not known if environment rendering uses [BSP](bsp.md) rendering, [portal rendering](portal_rendering.md), [raycasting](raycasting.md), something similar or whether it just utilizes its 3D model renderer for levels too, however there are some 2.5D simplifications going on as levels are defined as 2D (no room-above-room) and looking up/down is faked (even for the environment inserted "true 3D" models). The game's level editor shows levels use a square grid on which however it is possible to place even non-90 degree walls. There is also a [lightmap](lightmap.md) lighting system present allowing [dynamic](dynamic.md) lights -- a pretty advanced feature, though the lightmap only seems to be 2D, just as the level itself.