Off Topic :
FYI, for the benefit of anyone else struggling with a large background model, such as an urban area, here's a tip I learned the hard way.
The urban model in its own separate file was 6MB. After exploding most components in order to change the face material (manually & locally, as it turns out) the file size ballooned up to 11.5MB. When added to my own building model that produced a filesize apparently too large for my system to handle.
So I exported the urban model from SU8 to 3DS format. That step reduced the file size back down to 2.3MB. Unfortunately, it also undid most of my laborious material changes. So, next time I'll export the complex background to 3DS before I attempt to make material changes.
PS---The Global Material Changer script still didn't work on the 3DS file. Instead it caused a lockup & shut-down. Maybe even the reduced total file size is just too big for my system. 4MB of physical memory (plus 256MB of graphics card memory) should be enough for most SU models. But I noticed that my Task Manager showed almost no Virtual Memory in use, even when the CPU was maxed-out. The system Page File is set for Windows to automatically adjust to memory demands. But it doesn't seem to be taking much of the load off the physical memory.
