Good news. Arvid Schneider is back from a small vacation and posting Arnold vids again. His latest shows how you can work with Arnold Stand-ins when rendering.
keep your working scene light and workable by deferring the loading of geometry data until render time
Arnold is a production-level renderer, which means that it can easily fit into a production pipeline with the features that you would expect. Like other production renderers, Arnold allows you to keep your scenes light and manageable by deferring the load of geometry until render time. In Arnold these are called Stand-ins. Models doest get loaded until they are needed. In Arnold’s case, until a ray hits the bounding box of the Stand-in.
Watch a nice walkthrough of the Stand-in system, brought to you by Arvid, who shows how to get started with this feature. Because Arnold is pretty much the same on all platforms and hosts, it is important to note that Stand-ins can be uses within Nuke, Maya, or others. Arvid covers importing and exporting Stand-ins as well as rendering them with the Render View.