i have been tasked with building a few sky scrapers for a project at wotk (i am using unreal). because they are huge, i was assuming that using geo was probably gonna be too costly. i was messing around with the idea of using normal mapped sections and duplicating them. this reduces the number of polys onscreen which is good because there will be blocks at a time loaded. so here is where the question comes in:
if i create a mesh with 2 uv sets, 1 that is effected by just the normal and a second set that is layed out differently that has my diffuse and a paralax window (like in the materials video), am i undoing what i did with geo? better yet, how can i tell when a texture becomes too expensive as opposed to geo?