I've noticed that in World of Warcraft, fixed objects suddenly appear as the player moves towards them and then vanish as they move away. For example, as the player moves along a road, a building will suddenly appear by the side of the road, when a moment earlier it was not there and if the player moves back a little, the building will vanish. What is this called?
The "View Distance" setting allows the user to mitigate this behaviour by causing things that are further away to be visible at the expense of system resources.
In conversation, I've noticed one person use the word "Pop" when referring to this, so in an effort to find the correct term I came across the following wikipedia article Popping(computer graphics), which seems to be very much related to the behaviour I have described, but differs in that it's about transitions from one level of detail to another, rather than the instance of an object suddenly appearing out of nowhere.
What is the term used to describe this?
Best Answer
Different users will have a term they use, and some may be more popular than others, or more specific to a certain situation. Blizzard, themselves, refrain from using a specific term for the behavior, when talking about it in a blog concerning graphical improvements in the upcoming expansion, Legion. Instead, they simply explain why it happens.
I will offer an explanation on both Possible Terms and Related Terms, and suggest that you choose your terminology for the situation. If you have to bring up the behavior in the middle of a raid, you do not want to add to the confusion by having to explain technical jargon to 30+ other players. Likewise, more technical terms can more accurately define the exact occurrence you are experiencing.
I will also explain Draw Distance, the mechanic behind the behavior you are experiencing, to help further explain both the terms and why this is actually happening.
Possible Terms
OK, so you know why it happens, now. But what do you call it? My recommendation: whatever you want to. The thing about draw distance is that it exists in some form in basically every video game you have ever played. Assuming your computer meets the recommended system requirements for running World of Warcraft, you should never run into a situation where you were adversely effected by your ability to see further than the maximum draw distance. As a result, you should never run in to a situation where it is imperative that you inform other players of the limitations of your draw distance. It just doesn't happen.
Related Terms
There are some other terms you may come across in relation to draw distance, and the 'popping' effect of game objects. It might be worth addressing these terms, and the correct use, in understanding the terms listed above.
Draw Distance
What is it?
Changing the View Distance does not just mitigate the behavior - it directly relates to why it is behaving that way, in the first place.
When you play any game, you are typically looking through a "game camera". In Game Development these cameras can become quite complex, but in layman terms, they simulate real cameras to determine how to render the scene to the computer monitor1.
One important value a game camera holds is it's minimum and maximum draw distance. This tells the camera exactly what it can see, to draw to the screen. Before rendering any game object, the camera determines whether the object falls between the minimum and maximum draw distances. Depending on the circumstance, the camera may entirely ignore an object that crosses outside of the draw distance boundaries, or instead only draw the object as far (or as close) as the draw distance allows.
As you move forward, objects outside of the draw distance move closer. If these objects move inside of the draw distance, they will be drawn, but at this point, that is as simple as it gets. Ultimately, the object will "pop up" on the exact frame where the object is first within the draw distance. Likewise, it will disappear again, on the exact frame where the object first moves outside of the draw distance. By itself, this can result in some pretty rough looking graphics, so other things go into making it all look better.
1 OK, so it is not quite that simple, but for the purpose of this answer, that is as much as we need to know. 2 It would be desirable if we could draw "forever" (or as good as the human eye can see). In computing, this would lead to extensive resource use, and potential critical failure. As a result, the limitation enforced by the draw distance is a necessary, sometimes undesired, solution to a known graphical issue. Alternatively, efforts to smooth the draw distance could conflict with poor graphic card configurations, especially in cases where the graphic card is itself faulty.