Although 3D texture based volume rendering guarantees to obtain image quality almost interactively, it is difficult to maintain this interactivity when the technique has to be exploited on large data sets. In this paper, we propose a new texture memory management policy that substitutes the classical assignation policy of one texel per voxel, applied for the volume representation in texture space, for a more synthetical one that benefits of nearly homogeneous regions and areas of no interest of the volume. Based on this new policy a 3D texture based Octree Volume Visualization algorithm, that combines 3D texture hardware and hierarchical representation of volume data, is presented. The algorithm allows multiresolution renderings of very large data sets and guarantees high image quality at regions of special interest. The simplified representation applied to the non-interesting regions of the volume improves rendering speed.