Contents  Introduction  What is IM?  Execute Buffers  Steps to Create  an Application  Scene Management  Sample App  IM Objects  DrawPrimitive  Comparing Modes  Summary  Printable version

Immediate mode is the lower-level interface to Direct3D and is used by the retained mode, for all its operations, transparent to the developer. Immediate mode is nothing but a very thin layer over the real-time 3D hardware present. It gives access to the features of the hardware and provides optional rendering support for the features not supported by the hardware.

Though the immediate mode provides access to the underlying hardware, it does so in a device independent manner and provides a device independent way to communiate with the acceleration hardware at the lower level.

A very important aspect about the immediate mode is that it does not provide a built-in geometry engine. The limitation due to this, is that the developer has to provide the implementation for the different modules of the rendering pipeline. A big advantage is that the developer can use her own rendering and scene management algorithms, which might be more efficient and faster than the geometry engine provided by the retained mode.

Next : What is IM?