3D Texture mapping

I am trying to render some 3 dimensional objects and map 3D texture to them. I have polygonized the data using marching cubes algorithm and now want to add 3D texture using openGL. I guess, the class that is going to help me is “glTexImage3D”, but it seems it can map texture only if the data is in voxel format. Is there anyway I can directly map 3D texture to my polygonized data.