I...didn't get your question correctly. Do you want to know how 3D scenes are rendered? Like, the process of rasterizing, vertex and pixel shading and display on the monitor?
About Software Renderers. There's POV Ray, Mental Ray, the 3DS Max Scanline, Brazil. I don't think they use DirectX as it is an API designed to allow easy access to hardware capabilities. It's only useful for real-time stuff, regarding 3D rendering. Also I believe D3D doesn't even render the stuff, it justs tells the graphic card to do the hard work. It's more like a brain, not muscle.
Take RayBox, for example, a mini-mainframe ray-tracing device thingy. It uses it's own software renderer.
About Software Renderers. There's POV Ray, Mental Ray, the 3DS Max Scanline, Brazil. I don't think they use DirectX as it is an API designed to allow easy access to hardware capabilities. It's only useful for real-time stuff, regarding 3D rendering. Also I believe D3D doesn't even render the stuff, it justs tells the graphic card to do the hard work. It's more like a brain, not muscle.
Take RayBox, for example, a mini-mainframe ray-tracing device thingy. It uses it's own software renderer.