This attribute defines which texture image shall be used for texturing. If d is 1, the one dimensional image set with TEXIMAGE1D ( see 6.4.11) will be used, if d is 2, the two dimensional image set with TEXIMAGE2D (see 6.4.12) will be used, if d is 3, the three dimensional image set with TEXIMAGE3D (see 6.4.13) will be used. If d is zero, texturing is disabled.
d must be a number node, and have the value 0, 1, 2, or 3.