..ok afko..first of all, if you wanna export lightmap from 3DSMAX, you have to make all your level segments as a one mesh (dont use collapse), but still with hierarchy, what is important for later use of your geometry within game code..so, once selected, your mesh will apear in your object selection box...be careful with chanels you using for lightmap, since its possible to erase previous UV map slot with it..anyway, if you want specific details, be free and email me and i will provide you all details about 3DSMAX lightmaping..