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3D Rendering
In computer graphics 3D rendering is concerned with computing images that represent a projected view of 3D objects through a virtual camera. There are many methods and algorithms for doing so differing in many aspects such as computation complexity, implementation complexity, realism of the result, representation of the 3D data, limitations of viewing and so on.
A table of some common rendering methods, including the most simple and most advanced ones, follows. Note that here we talk about methods rather than algorithms, i.e. general approaches that are often modified and combined into a specific rendering algorithm. The table should help you craft an ideal 3D rendering algorithm for your program.
The methods may be tagged with the following:
- 2.5D: primitive 3D, often called pseudo 3D or fake 3D, having significant limitations e.g. in degrees of freedom of the camera
- off: slow method usually used for offline (non-realtime) rendering (even though they indeed may run in real time e.g. with the help of powerful GPUs)
- IO vs OO: image order (rendering by pixels) vs object order (rendering by objects)
| method | notes |
|---|---|
| 3D raycasting | IO off, shoots rays from camera |
| 2D raycasting | IO 2.5D, e.g. Wolf3D |
| beamtracing | IO off |
| billboarding | OO |
| BSP rendering | 2.5D, e.g. Doom |
| conetracing | IO off |
| "dungeon crawler" | OO 2.5D, e.g. Eye of the Beholder |
| ellipsoid rasterization | OO, e.g. Ecstatica |
| flat-shaded 1 point perspective | OO 2.5D, e.g. Skyroads |
| image based rendering | |
| mode 7 | IO 2.5D, e.g. F-Zero |
| parallax scrolling | 2.5D, very primitive |
| pathtracing | IO off, Monte Carlo, high realism |
| portal rendering | 2.5D, e.g. Duke3D |
| prerendered view angles | 2.5D |
| raymarching | IO off |
| raytracing | IO off, recursive raycasting |
| segmented road | OO 2.5D, e.g. Outrun |
| shear warp rednering | IO, volumetric |
| splatting | OO, rendering with 2D blobs |
| triangle rasterization | OO, traditional in GPUs |
| voxel space rendering | OO 2.5D, e.g. Comanche |
| wireframe rendering | OO, just lines |
TODO: find out how build engine/slab6 voxel rendering worked and possibly add it here (from http://advsys.net/ken/voxlap.htm seems to be based on raycasting)
TODO: VoxelQuest has some innovative voxel rendering, check it out (https://www.voxelquest.com/news/how-does-voxel-quest-work-now-august-2015-update)