I haven't tried too much of modular pieces in UT3, but aren't, say, 16 meshes with 256 shadowmaps are as heavy on memory and calculations as 1 mesh with 1024 shadowmap? In any case, for this building a shadowmap can be even 1024. Ideally 2048, but it may come out not bad with 1024. For even better result UVs for shadow map…