Nvidia has recently uploaded APEX related presentation called “APEX : Creating scalable immersive game environments” from their SIGGRAPH 2010 sponsored sessions list.
Usual overview of APEX framework and current modules (like Destruction and Clothing), which are already familiar to us from past GDC10 and SIGGRAPH09 sessions, is followed by topic never described in detail previously – Scalability and LOD features inside APEX (starts at 32:55).
In general, it’s devided into two components – scalable parameters for each of the modules (like number of particles or cloth vertices), that can be adjusted during authoring to fit into platform computing capabilities..
..and dynamic LOD system, that manages resources destribution between actors and modules, based on current situation and resources budget (for example, clothing on character closer to the camera will be simulated with higher fidelity).
Now, as we know almost everything about APEX, we just need to wait until it will be released to public (standalone, or integrated into popular engines like UE3).