Concept by Sung Choi : sung-choi.com (via polycount).

I modeled everything in Maya, using subdivision surfaces for all of the high poly meshes (except for the egg detail texture, which was done in zBrush), baked the occlusion, normal map and colour masks in xNormal and assembled everything in Photoshop. The text on the decals and the exterior panel is abstracted lorem ipsum and I used a few vector shapes to recreate the exterior panel design. 

I deviated slightly from the proportions of the concept, making the exterior side panels stick out a bit less, so that it would look as natural as possible with a character model. I added hinges to the exterior door and a lip to the inside of a case to make it seem a bit more rugged and I simplified the straps so that it would be easier to animate the backpack being removed or put on. For the inner box mesh, I changed the bevels on the front door into a handle and changed the handle on the side to a latch, imagining that a character would have to pull the box and base out of the backpack without the door opening.