IdTech4 Open Source: Difference between revisions

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|Graphic
|Graphic
|No access to the Z-Buffer. Without access to this data, any depth-based fragment shader effects like SSAO or Depth of Field require an extremely expensive z-pass render.
|No access to the Z-Buffer. Without access to this data, any depth-based fragment shader effects like SSAO or Depth of Field require an extremely expensive z-pass render.
|Performance increase.
|Performance increase. More effect options.


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Revision as of 15:52, 29 October 2010

id Software has a long history making the code to their engines open source after a while. Even after being sold to Zenimax, this trend continued. The source code can be found on the officiel FTP server from id software.

So there is hope that idTech4 (the engine behind Doom 3 and Quake 4) will also be open sourced. For The Dark Mod this means that we can fix a long list of issues that are currently not possible.

Here is a small, incomplete list, in no particular order:

Todo: add more examples

Category Issue Possible outcome
Sound EAX does not work under Linux. Works there, too.
Graphic The lightgem needs to render to a texture and transfer this texture back to the CPU via a complicated in-memory file scheme. Performance increase.
Graphic No instancing. Multiple instances of the same model are all rendered one by one, instead of uploading it once and then telling the graphic card to render them all in one go. Performance increase.
Graphic No access to the Z-Buffer. Without access to this data, any depth-based fragment shader effects like SSAO or Depth of Field require an extremely expensive z-pass render. Performance increase. More effect options.
Coding Single-threaded coding. It may be possible to divide the sub-systems into separate execution threads for processing on separate cores once the source code is available. The game Prey has implemented this type of change to Id Tech 4. On the extreme side of concept, OpenCL could be used to perform AI path-finding, or physics calculations. Performance increase.

See also