lass="term"><code class="constant">GL_UNPACK_IMAGE_HEIGHT</code></span></dt><dd><p>
                        If greater than 0,
                        <code class="constant">GL_UNPACK_IMAGE_HEIGHT</code> defines the number of pixels in an image of
                        a three-dimensional texture volume.  Where ``image'' is defined by all
                        pixel sharing the same third dimension index.
                        If the first pixel of a row is placed at location
                        <