gluLookAt

Definition: include pGUI.e
include opengl.e
include glu.e

gluLookAt(sequence eye, sequence center, sequence up)
Description: The gluLookAt function defines a viewing transformation.

eye: The position of the eye point, as {x,y,z}.
center: The position of the reference point, as {x,y,z}.
up: The direction of the up vector, as {x,y,z}.
Remarks The gluLookAt function creates a viewing matrix derived from an eye point, a reference point indicating the center of the scene, and an up vector.
The matrix maps the reference point to the negative z-axis and the eye point to the origin, so that when you use a typical projection matrix, the center of the scene maps to the center of the viewport.
Similarly, the direction described by the up vector projected onto the viewing plane is mapped to the positive y-axis so that it points upward in the viewport.
The up vector must not be parallel to the line of sight from the eye to the reference point.

The matrix generated by gluLookAt postmultiplies the current matrix.
See Also: glFrustum, gluPerspective