Parameters target Specifies the target texture.
Level 0 is the base image level. Level n is the nth mipmap reduction image. Specifies a texel offset in the z direction within the texture array. Description Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. The glTexSubImage3DEXT subroutine redefines a contiguous subregion of an existing three-dimensional texture image.