1. An adaptive rendering apparatus using a hierarchical structure in a 3D image, the adaptive rendering apparatus comprising: a processor that executes: a cell data provision unit to divide an original 3D image into a plurality of lattice cells that are connected to one another in a hierarchical structure according to predetermined rendering conditions and outputs a plurality of cell data of an area of the original 3D image corresponding to the lattice cells; and a rendered image generation unit to generate a 3D rendered image by arranging the cell data output from the cell data provision unit according to the hierarchical structure, wherein a lattice cell belonging to a particular level in the hierarchical structure is divided into a plurality of lattice cells belonging to a level directly below the particular level, and each of the lattice cells in the level directly below the particular level is smaller than the lattice cell of the particular level, and a lattice cell corresponding to a predetermined portion of the original 3D image belongs to a lower level in the hierarchical structure than a surrounding lattice cell, wherein the cell data of each of the lattice cells has voxel values, wherein the rendering conditions include at least one of the amount of time required for generating the 3D rendered image, and a maximum among the resolutions of the 3D rendered image, wherein the original 3D image is a 3D scenic image containing a 3D object image, and a lattice cell corresponding to the 3D object image belongs to a lower level in the hierarchical structure than a lattice cell surrounding it, wherein the 3D object image is a portion of the original 3D image representing a person or an object, and the 3D scenic image is a portion of the original 3D image representing a place where the person or the object represented by the 3D object image is located, wherein the 3D object image is represented based on the voxel values and the 3D scenic image is represented based on the hierarchical structure.