The official Star Wars: The Old Republic community forums have been abuzz with complaints from players who've been wondering why most high-resolution textures in BioWare's MMO have gone missing after the game launched. After some promised investigation, word has finally come out as to why said textures have vanished, and while it makes sense, it's probably not the answer that player were hoping for.
In an exhaustive post on the SWTOR forums, Senior Online Community Manager Stephen Reid explains that the high-resolution textures--which players were able to enjoy before the game's official public launch--were removed due to a "deliberate decision by the development team."
Apparently the decision to remove high-resolution textures rendered outside of the cinematic cutscenes was due largely to the fact that in an MMO, it's not really possible to know how many characters will be on screen and viewable at a given moment. Reid explains that in the case of SWTOR, "we discovered that using our 'maximum resolution' textures on in-game characters during normal gameplay could cause severe performance issues, even on powerful PCs." Places like "popular gathering places," "Operations with large teams," and Warzones were particularly affected.
BioWare elected to solve this problem by using something called a "Texture Atlas," which Reid explains in detail.
When a character in the game is 'seen' by another character - ie, gets close to your field of view - the client has to 'draw' that character for you to see. As the character is 'drawn' for you there are a number of what are known as 'draw calls' where the client pulls information from the repository it has on your hard disk, including textures, and then renders the character. Every draw call that is made is a demand on your PC, so keeping that number of draw calls low per character is important. With our 'maximum resolution' textures a large number of draw calls are made per character, but that wasn't practical for normal gameplay, especially when a large number of characters were in one place; the number of draw calls made on your client would multiply very quickly. The solution was to 'texture atlas' - essentially to put a number of smaller textures together into one larger texture. This reduces the number of draw calls dramatically and allows the client to render characters quicker, which improves performance dramatically.
Given that the same rules don't apply to cinematic dialog sequences--since the developer has "control over exactly how many characters are rendered and can ensure that the game performs well," those sequences still support the beefier textures.
Perhaps the only real surprise is how Reid addresses what he refers to as a "UI bug," which led to much of the confusion. The "bug" pertains to how players can still select "Low," "Medium," and "High" graphics options. The UI should just reflect "Low" and "High" options, wherein the old "Medium" is the new "High." Players understandably assumed that all three settings would reflect themselves appropriately in-game. It's an oversight that's let to some completely avoidable fan-frustration, and it's not unreasonable to expect that a future patch will remedy this issue.
That said, Reid states that BioWare looking for ways to improve the game's presentation even further. "With that said, we've heard your feedback here loud and clear," Reid notes in his post's closing statements. "The development team is exploring options to improve the fidelity of the game, particularly for those of you with high-spec PCs. It will be a significant piece of development work and it won't be an overnight change, but we're listening and we're committed to reacting to your feedback."