Overview of Direct3D 11 - Practical Rendering and Computation with Direct3D 11 - page 5

From a high level, there are currently two general pipeline paradigms—one which is
used for rendering, and one which is used for computation. Strictly speaking, the distinc-
tion between these two configurations is somewhat loose, since they can both be used for
the other purpose. However, the distinction exists, and there is a clear difference in the
two pipelines' capabilities. We will discuss both pipelines, beginning with the rendering
pipeline.
1.2.1 Rendering Pipeline
The rendering pipeline is the origin from which the modern GPU has grown. The initial
graphics accelerators provided hardware vertex transformation to speed up 3D applica-
tions. From there, each new generation of hardware provided additional capabilities to
perform ever more complex rendering. Today, we have quite a complex pipeline, with
significant flexibility to perform nearly any algorithm in hardware. Topics are published
regularly describing new techniques for using the latest hardware such as (Engel, 2009)
and(Nguyen, 2008). The level of advances in real-time rendering has really been quite
staggering over the last 5-10 years.
The rendering pipeline is intended to take a set of 3D object descriptions and convert
it into an image format that is suitable for presentation in the output window of an applica-
tion. Before diving into the details of each of the individual stages, let's take a closer look
at the complete Direct3D 11 rendering pipeline. Figure 1.2 shows a block diagram of the
pipeline, which we will see many times throughout the remainder of the topic, in several
different formats.
Here, the two different types of pipeline stages, fixed-function and programmable,
are depicted with different colors. The fixed-function stages are shown with a green back-
ground, and the programmable stages with a blue background. Each stage defines its own
required input data format and also defines the output data format that it will produce when
executed. We will step through the pipeline and briefly discuss each stage, and its intended
purpose.
Figure 1.2. The complete Direct3D 11 rendering pipeline.