1991-2006 Silicon Graphics, Inc. gluUnProject 3G gluUnProject map window coordinates to object coordinates GLint gluUnProject GLdouble winX GLdouble winY GLdouble winZ const GLdouble * model const GLdouble * proj const GLint * view GLdouble* objX GLdouble* objY GLdouble* objZ winX winY winZ Specify the window coordinates to be mapped. model Specifies the modelview matrix (as from a glGetDoublev call). proj Specifies the projection matrix (as from a glGetDoublev call). view Specifies the viewport (as from a glGetIntegerv call). objX objY objZ Returns the computed object coordinates. gluUnProject maps the specified window coordinates into object coordinates using model, proj, and view. The result is stored in objX, objY, and objZ. A return value of GLU_TRUE indicates success; a return value of GLU_FALSE indicates failure. To compute the coordinates objX objY objZ , gluUnProject multiplies the normalized device coordinates by the inverse of model * proj as follows: objX objY objZ W = INV ⁡ P ⁢ M ⁢ 2 ⁡ winX - view ⁡ 0 view ⁡ 2 - 1 2 ⁡ winY - view ⁡ 1 view ⁡ 3 - 1 2 ⁡ winZ - 1 1 INV denotes matrix inversion. W is an unused variable, included for consistent matrix notation. gluProject, glGet Copyright 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.