Is there a good 3d realtime software renderer with features similar to OpenGL/DirectX? Something similar of what cairo or anti-grain do for 2d, but in 3d.
I actually just know Mesa witch has a software OpenGL implementation , and Coco3d.
It should be open source :)
OpenGL is open source, and should fall back to software rendering in the absense of 3D hardware on the system, provided that all the proper libraries are installed.
You could have a look into Orge 3D engine assuming you want an abstraction from the raw GL to something that already has a lot of the key features. It's open source too.
I believe the OpenSceneGraph has grown to be pretty competent and widely used.
Technically OpenGL is just a standard, but there are OSS implementations available for download. I'm not sure you want a reference OGL driver though.
For 3d libraries, there are loads. Irrlicht, CrystalSpace, Ogre3d, to name just 3 off Sourceforge's trove list.
For a pixel rendering engine why not have look at the DOOM rendering engine sources.
Another smaller and more standard API/OpenGL implementation called TinyGL could be something to look at too.
The only major open source real-time software renderer besides Mesa I know of is the Quake I engine. However, it's not up to par with current OpenGL or Direct3D capabilities.
If you can do without the source code, you could have a look at the Microsoft WARP10 renderer. It's a high performance implementation of Direct3D 10 on the CPU.
Check out Coin, an implementation of OpenInventor maintained by the company I'm employed by. It's licensed under a dual licensing model - GPL for free/opensource software. It's being actively developed and uses OpenGL to do rendering. It works on "all" platforms and can be easily integrated with Qt.