I don’t have experience in game development, but I do in 3D modelling and animating, here goes my guess (I’m skipping any step that doesn’t deal directly with creating the models):
1.- Create concept art. This is usually done by one concept artist, they’re passed back and forth with the art department until the look is approved.
2.- Concept art is passed to the 3D modeler, who creates the actual 3D model. The textures might be made by the same artist, but it can also be created by a dedicated texturer, who also would create things like bump maps, reflection maps and so on. This step might involve going back and forth with step 1, because sometimes things that look good on paper (or on the screen) don’t look as good when you make the change to 3D, specially when you consider the engine limitations (amount of polygons allowed for each model, resolution of the textures and so on). Also several iterations (minor or major) of each model might be created until the art department approves it. If it’s an armor set, it’s most likely done on a human model, and both male and female versions are made (so twice the amount of time needed). Note that I believe this is where the dye channels are defined by using texture maps.
3.- Adjusting to different races. Once the model is approved (most likely done on a human model), then if it’s armor it’s adjusted for the other races, so that means adjusting the model for basic sylvari male/female, norn male/female, asura male, charr male/female… charr body type is different enough on male and female that I’d say some manual adjustment might be needed on most pieces of armor. That can be as easy as just scaling and resizing a little bit, to completely remodel the piece. Gloves and shoulders are probably the easiest, helm the second easiest (though it would require heavy remodeling to fit on Charr) with chest and leg armor probably hardest ones, which is why I believe when we see single armor pieces they’re usually shoulder – gloves – head.
4.- Rigging. This can be done by the same modeler, but usually it’s someone else that does it. This involve making the models work and deform with the character’s skeletons, which can be very easy when it comes to weapons, and medium to very hard when it comes to armor pieces, because weapons basically just move and swing, while armor needs to deform based on the movements, and ideally you need to take care of the the binding to make it deform properly (so you don’t have a metal plate, for example, bending and stretching like rubber). Usually this is done as the last step before importing because depends heavily on having a finished model, but might also mean that the model might be sent back to previous steps to fix things that might break the rigging.
5.- Importing it into the game. If I had to guess, this is where things like particle effects, glows and physics are added
6.- Testing, testing and more testing. If it’s a weapon model, test it for it to look good with all different character types and animations, if it’s armor, also test to see if it looks good on different extremes of body types, that the rigging doesn’t break while on them, and so on. Note that this might make it go back to any of the previous steps to fix something or even do it again.
7.- Once everything is ready, ensure that the armor has the expected clipping issues with Asura’s ears and Charr tails, add them if they’re absent..
(j/k)
Depending on how many people have working on it, I’m guesstimating few weeks of work for a full armor set. Note that that doesn’t mean it’s all they’re working on, a 3D modeler, for example, is probably be working on something else after sending a model for rigging, and several modelers might be working on several things at the same time.
It’s a pile of Elonian protection magic, mixed with a little monk training,
wrapped up in some crazy ritualist hoo-ha from Cantha.
A real grab bag of ‘you can’t hurt me. They’re called Guardians.