This is less of a Solidworks question and more of a general solid modelling question. If you have a model with a known but irregularly shaped volume, are there any utilities that can create a best fit volume packing of another known shape? Preferably with some other constraints such as "always keep face Y parallel with plane X" and even better if it can be fed a variety of shapes to best optimize the most number of each shape to best fill said volume.

For example, if you had all the different sizes of UPS boxes available and needed to fit them into a cavern of known volume to leave the last amount of 'air' afterwards (keeping in mind, "this way up"). (That isn't the application, but similar intent). Any ideas?