## F

face
  A single polygon in a mesh.
fade
  The period between the central, or sustain, portion of a force feedback effect and its end.
field
  Data for one-half of a single video frame within a video stream. Each field contains data for every other scan line. Fields are sent and received in odd field, even field order.
field polarity
  Quality determining whether a field is an even field or an odd field. Odd fields are defined when the trailing edge of VREF does not occur during a scan line. Even fields are defined as when the trailing edge of VREF occurs during a scan line.
flip
  The process of swapping the addresses associated with the back and front buffers. This effectively swaps the image in the back buffer to the front buffer, thereby displaying the image.
flipping chain
  A series of surfaces, attached to each other, that can be flipped. See also flip.
flipping surface
  Any piece of memory that can be flipped. See also flip.
frame
  An invisible box that provides a frame of reference for objects in a scene. Objects can be placed in a scene by specifying their spatial relationship to a relevant reference frame. Visual objects take their positions and orientations from frames. Also, a single image from a movie or animation.
front buffer
  The first buffer in a flipping chain. In many cases, this will be the visible primary surface. In other cases, such as a flipping chain of textures, the front buffer is the surface the 3-D engine will get the texture from, but it is not the primary surface and is not displayed. In the case of flipping overlay surfaces, the front buffer is displayed, but is only a surface overlaid on the primary surface. See also primary surface.
front clipping plane
  The near boundary of a viewing frustum. Any object closer to the camera than the front clipping plane is not rendered. The height of the front clipping plane defines the field of view. See also back clipping plane.