• Intel® Graphics Performance Analyzers 2020 R1
  • 03/31/2020
  • Public Content
Contents

Cull None, Cull Clockwise, Cull Counter-Clockwise

Usually, an application uses a consistent orientation for all graphics primitives. This orientation may be clockwise or counter-clockwise, depending on the order of vertices. This orientation determines the view normal of each primitive, and this normal determines whether the primitive is forward- or backward-face oriented with respect to the viewer or camera - typically backward-facing primitives are not rendered. Use of these override modes may help uncover errors in how you have defined the orientation of primitives in the scene.
Use the
Cull Counter-Clockwise
or
Cull Clockwise
override modes to remove the rasterization of all triangles oriented to the camera or turned away from the camera correspondingly. The culling mode applied to a geometry having an opposite orientation order of primitives reveals internal sides of that geometry because all front-faced primitives become invisible.
Use of the
Cull None
override mode usually has no visual effect but may decrease application performance because both visible and invisible primitives are rasterized. When using this override mode, Graphics Frame Analyzer disables culling so all primitives are rendered, independent of whether they are clockwise or counter-clockwise-oriented.
NOTE
Certain games use a full-screen quadrangle with the render target texture to expose the frame. If you apply the
Cull
Clockwise
state override to such games, certain triangles will not be written to the back buffer and you will see blinking of the screen. This is the result of swapping the front buffer with old content and the back buffer with cleared content (commonly referred to as a "Swap Chain").

Product and Performance Information

1

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Notice revision #20110804