I noticed in Stress Test 42, that items, and the motorcycle helmet in particular, (from what I've primarily seen) seem to disappear frequently, b/c of occlusion, or just because of low graphics settings. Sometimes you'll miss a object that you can't see from a distance, but if it's for optimization I can understand, but you should at least be able to see that some form of geometry from a distance. Even if it's very unclear and blurry.