gluPerspective
[New
- Windows 95, OEM Service Release 2]
The gluPerspective function sets up a
perspective projection matrix.
void gluPerspective(
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GLdouble fovy, |
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GLdouble aspect,
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GLdouble zNear, |
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GLdouble zFar |
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); |
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Parameters
fovy
The field of
view angle, in degrees, in the y-direction.
aspect
The aspect
ratio that determines the field of view in the x-direction. The aspect ratio is
the ratio of x (width) to y (height).
zNear
The distance
from the viewer to the near clipping plane (always positive).
zFar
The distance
from the viewer to the far clipping plane (always positive).
Remarks
The gluPerspective function specifies a viewing
frustum into the world coordinate system. In general, the aspect ratio in gluPerspective
should match the aspect ratio of the associated viewport. For example, aspect
= 2.0 means the viewer s angle of view is twice as wide in x as it is in
y. If the viewport is twice as wide as it is tall, it displays the image
without distortion.
The matrix generated by gluPerspective is
multipled by the current matrix, just as if glMultMatrix were called
with the generated matrix. To load the perspective matrix onto the current
matrix stack instead, precede the call to gluPerspective with a call to glLoadIdentity.
See Also