How to UV map exactly?

New reply on “HOW do I UV MAP this whole house? I need to import it into UnrealEngine4 to be VR. Materials are attached to the models here in 3dmax but i am planning on reapplying them in Unreal. SO do the materials affect UVs, if so should i delete them here in 3dmax? THE WHOLE HOUSE IS ONE BIG “”“ATTACHED””" MODEL* (furniture,walls, house) with multiple material IDs (multi-sub objects) ,dividing the 1 MODEL* surfaces into its separate materials for each separate peice of furniture…wall… etc. SO THE “multi-sub objects” are dividing the materials on that one model. NOW i get GREEN UVs on the UV map which i can’t flatten or pad… only tried relaxing which worked but just made a mess since i didn’t flatten or normalize or padding or anything. So how can i finish UVmapping this and exporting to UnrealEngine4? Is “attaching” ALL the models together into one big house model the best for UV then EXPORT INTO UNREAL>? After finishing the UVmap, DO I EXPORT FILE as .obj?"