Assembly: Microsoft.Xna.Framework (in microsoft.xna.framework.dll)
The number of non-occluded pixels (indicated by PixelCount) can differ based on the platform.
For Windows games, PixelCount represents the number of pixels that passed the depth and stencil tests. This does not include sprite batch drawing (because the depth test is turned off) or calls to GraphicsDevice.Clear.
To achieve consistent results across all platforms, use occlusion queries only when the depth buffer is enabled. In addition, avoid calling Clear or changing the assigned render target inside an occlusion query begin/end block.