What is UV count?
polycounter lvl 14
I am passing a test for a compagny, they give me a limit of "1500 UV" for a model. Is "UV count" a synonyme for triangle count?
Thanks by advance!
Thanks by advance!
Replies
UV almost always means texture coordinates. But setting a 1500 limit for texture coordinates seems really odd to me (and I've been doing this for >16 years). Anyhow people usually use "TV" to mean texture coordinate vertices.
They might be using UV to mean something like "ultimate vertices", which would be the # of vertices that the model is split into by the game code. See this article for an explanation. Really difficult to calculate this number though.
Or the person who wrote up the instructions didn't quite understand what they where given... Or they could know exactly and its some weird engine requirement. It would be interesting to see what they have to say.
Turned out after googling, some person at that studio did not knew his vocabulary and used it all over the website. Maybe it was a internal term the studio used (like id software not referring to normal mapping internally) because they did not knew better the first time they were confronted with it.
anyway the number 1500 is a odd number because in most cases you would refer to something that is the result of powers of 2, e.g 2^8 = 256; Having the limit of tetxure faces sperated from the object model makes no sense either because you would rather define the limit by the object triangle count it self.
I have a vague assumption that they mean texture size (and mix it up with 'UV'), lets see how it turns out
Maybe its just me but I think that'd be a damn good part of a test - people who don't ask questions and just nod their head without really knowing what you meant are hard to work with.
In this case UV count is the number of unique UV vertices... so it's probably a more accurate number for performance reasons than just a straight-up triangle count or vertex count.
If your object is all one material and has no split vertex normals then the UV count should be your final in-game vertex count.
Kinda makes sense to me, although I haven't ever heard anyone describe a budget in terms of UV count before.
as MoP said, you can see the UV count along with the usual stats in Maya viewport, but i don't remember seeing a UV count in any other app...
If you don't get all the info you need up front, its not the persons fault for not giving it to you. If you ask and they fail to provide the info, at least you have it on the books that you asked and they dropped the ball.
I think MoP's onto something. It's probably another way to gauge how effective applicants are at unwrapping. Counting UV verts would be closer to the final vert count that goes in the game. I think every map that gets applied gets its own set of verts? So if there is a normal map it doubles, a light map it triples? Don't quote me on that I can't remember where I read it...
If you're using 3dsmax you have to do it more manually by breaking the actual model at the uv seams then checking the vert count. I think the obj exporter can be set to break models along UV's, just reimport it and check the vert count? Or is there an easier way?
Since the only thing splitting verts will be UV seams. No hard edges.
Games break meshes at material breaks (multiple materials applied to the same mesh), smoothing breaks (hard edges), and UV seams, I think that's it. Then you have the final vert count that will be in game. BUT Technically they didn't ask for all that just UV vert count, so technically no not to meet their requirement.
One thing to note here, if your hard edge, uv seam, and material split all happens to be along the same edge, you're only doubling, not quadrupling the vertex count there.
Is there a script that will automatically do this in Max? it seems like one should exist.
The nice thing about Maya's hard/soft edges is that you can literally just go "get all UV border edges, make them hard edges", it's pretty much a 2-3 line script. Doing the same thing in Max and making it foolproof would be a lot more tricky.
Plus this solution isn't an ideal fix in some cases - for example you might have a UV seam in a place where it makes more sense to have a "soft" edge - in many cases this will result in a cleaner bake and less chance of a seam than if it was a hard edge. Still, for mechanical models with lots of 90-degree corners it can be quite handy especially if you UV seams are in fairly well-hidden places (which they should be anyway tbh!)
I thought exporting to .3DS did that in Max? I could be wrong, been a long time since I got frustrated about that damn 3DS format and decided never to use it again.
any chance you are gonna share this with the world ?!
because i am looking all over for a script that calculates the inevitable in game vert count and i cant find anything !
( when it comes to squeezing everylast vert out of a drawcalls vertexbuffer knowing the precise number in maya while building is KEY )
http://www.ericchadwick.com/examples/files/HaywoodTools-UberVertCount.mcr
excellent autodesk... simply marvelous
renderhjs created a script that works in max9 and lower that transfers the uv open boarders to edit poly like it should. It's a bit of a pain using max9 but luckily for me I had it installed.
Sadly they have an unmapped function in the customize menu, to select the UV boarders (or open edges as they call it) per shell or all at once, which is similar to Maya but you can't transfer it to edit poly so its useless... HOPEFULLY they work out the kinks in 2012... Not going to hold my breath tho.
I don't think forcefully breaking UV edges will give you an accurate UV/material, but it might get someone closer to an accurate number.