The Rendering Pipeline - Practical Rendering and Computation with Direct3D 11 - page 216

Figure 3.64. Several pixels of a rasterized triangle, which demonstrate how pixels are affected by their
proximity to each of the vertices.

By default, the type of interpolation used to generate these per-fragment attributes is
a perspective correct linear interpolation. However, the interpolation mode can be modi-
fied by adding an interpolation modifier before the type declaration of a pixel shader input
attribute. The available interpolation modes are listed in Table 3.2, with a brief description
of their behavior.

Interpolation Mode Interpolation Mode Description Description

Provides linear, perspective-correct interpolation. The interpolation is based on Provides linear, perspective-correct interpolation. The interpolation is based on

the center of the pixel.

linear linear , . ,

the center ot the pixel.
Provides linear, perspective-correct interpolation. The interpolation is based on

Provides linear, perspective-correct interpolation. The interpolation is based on
the centroid of the covered area of the pixel.

centroid centroid , ., _. , , . ,

the centroid ot the covered area ot the pixel.

nointerpolation nointerpolation Provides no interpolation. Attributes are passed as constants. Provides no interpolation. Attributes are passed as constants.

Provides linear interpolation without accounting for perspective effects. The

Provides linear interpolation without accounting for perspective effects. The
interpolation is based on the center of the pixel.

noperspective

noperspective . ,••,,, . ,

interpolation is based on the center ot the pixel.
Provides linear, perspective-correct interpolation. The interpolation is based on
the MSAA sample location, instead of the center of the pixel.

Provides linear, perspective-correct interpolation. The interpolation is based on
the MSAA sample location, instead of the center of the pixel.

sample

Table 3.2. The available attribute interpolation modes.

Multisampling Considerations

Direct3D 11 's rasterization pipeline is an efficient means of rendering 3D geometry with
performance suitable for real-time applications. However one of the fundamental draw-
backs of rasterization is that the image produced can suffer from noticeable aliasing ar-
tifacts. Aliasing is a term from the field of signal processing that refers to the effect that