So I've got the Orange Box, and I'm working on my first TF2 map. Early on I noticed that some of my models in Hammer aren't showing up in the game. I've determined that it seems to be only HL2 models that are unreliable... some seem to work, others don't, but TF2 models always work. For instance, HL2 furniture seems to mostly be no good, but the HL2 vehicles work fine. So, a couple of questions regarding this. First of all, I hadn't even realized until this point that HL2 stuff was mixed in with TF2 stuff. I've decided that it's probably best to stick with just TF models for thematic reasons, and I know how to filter out the HL models. However, should I decide that a HL2 model really would be nice to use, will this cause any problems for the users? In other words, if someone else, whether the server or the player, only has TF2 and not HL2 on their machine, will the model and the map still work for them? I've searched a bit and the answer seems to be "yes" but I'm not real clear on that point. Secondly, what about textures? Will there be any conflicts come up if I use HL2 textures on a TF2 map? This is something that seems a lot more likely to be useful without clashing with the standard TF2 stuff. Honestly I haven't even been paying attention to which game my textures are coming from, though my map is still in very early stages and I'm not doing much with them yet, so it wouldn't be a big deal to swap some out. Oh yeah, and thirdly... why was I having some, but not all, of the HL2 models poop out on me? Not a big deal, but it seems odd to me, so I'm just curious if anyone has an answer.