Texel Density : What It Means & How To Use It

so I get asked on a pretty regular basis what is Texel density and how should I be using it so this video will be a quick overview of what it is and how to use it in modo and more specifically how to use the text low density tools in modo so when it comes down to what Texel density is Texel density is a tool for art directors and technical artists to set a consistent visual feel to a game world so it's not about super high res or super low res but it's more about consistency so the end result being that when you walk into a world you know I go into a room and do a spaceship into whatever it is you look around everything looks like it belongs together it looks like it's part of a cohesive whole and that's the kind of thing that gets ruined when you have a super high-res prop sitting on a low res table and that kind of thing like your your brain won't accept that as a cohesive world so Texel density is is there to help the player to get into the world and to help the art team you know to express the world in the best way possible so I find that Naughty Dog are a fantastic studio to reference for this kind of thing they have a really good feel for Tex Lavin City their world their worlds are always very believable so if you look at this this screenshot I'm ignoring the foreground blurriness that's just the camera depth the field effect but you looking at the mid-ground the plants the mold the trim everything you see in there looks consistently detailed there's nothing that's overly dense thus nothing that's overly blurry it all hangs together nicely and here's another quick example now pay particular attention to this area right here we've got the wooden struts the barrel on top Drake and the wall behind them and the foliage above it all looks consistently beat hailed and that's what good Texel density looks like just for reference sake so we're inside a moto now and to give a quick demonstration of how to set up Texel density we'll just do a simple example here we'll create a flat piece of wall well make it let's say 100 by 100 which it it will make it 1 meter by 1 meter inside of the Unreal Engine so we'll go with that there's a 1 meter wall chunk now to get to the text live in 2d tools you go to the UV section and click on the text Lavin City button click that once and then drag it off and that will give you an a floating window that'll just hang there the whole time you can use it all throughout the session so when you're setting up your Texel density inside of modo there's a couple of values that need to get set up and it's not a hundred percent clear what these mean you until you start to work with it so the first thing we need to do is give modo a texture size now this doesn't mean that every texture in the game needs to be the same size but it it gives moto a reference point for for packing islands and that kind of thing and you'll see what I mean here in a second so we're gonna tell modo that our texture size is 1024 that's a pretty standard size actually it's kind of smaller these taste but we'll go with 1024 for now so that's the image size now the Texel density this is where we tell Emoto of the ratio of Units 2 to 2 pixels on the texture so I always set this to pixels because I find that easiest to work with and we say for easy reference to save 100 units you in the game world which we just said this thing is 100 by 100 which is 1 meter by 1 meter when you're inside of Unreal Engine just keep that in mind so I'm gonna say that 100 units covers 1,024 pixels so with that ratio set up what that means is that this this 1 meter by one meter block should be exactly one texture tile and that's the general ratio that will go up will get applied to everything now if I stay consistent with these values so once you have that set up you want to select your UV island hit one of the apply buttons now what that's gonna do is Moto's gonna take that ratio that you said and look at the texture size and rescale the island accordingly so my tell us will apply it bumps the island up this big and you can see that as exactly that exactly fills my zero to one space because that's what I said I have at 1k texture and 100 units covers 1k boom so it fills the whole space for example purposes let's say that I told modo that I had a a your a 2k texture but I still kept this same ratio your hit apply drops down to half size because now I can fit four of those onto the texture and maintain this same ratio if I go smaller you know then it gets weird then I apply it and it's like my motifs like well yeah I can only get half of that wall onto one texture size or onto one texture tile so if I throw a 512 texture onto this wall it's going to tile twice horizontally and vertically but so you'll have to play around with that a little bit to see how that feels but that's the general mechanics of it and this is really helpful if you have a prop that you've already unwrapped or you know you change the text Allah Vince if you later let's say that kind of thing and you've got a whole bunch let me just make a few duplicates to this thing and we'll edit it out and make them you know some different sizes and things and just try to get just try to pretend we have these UV Islands and they're all so when it comes to having an existing prop like this what you need to do is you know to open your prop up and select the Eevee Islands yet make sure your ratio set up correctly in the hit the apply overall button now apply over all sets all the UV Islands to be the same text limit or sorry to match the Texel density that you specified and it's done that now you can see we still have this one piece that's going 0 to 1 0 to 1 but it would be of the pieces that are there outside the zero to one space now but they are you at the correct density now if this is something you want to texture uniquely that means that these pieces are going to have to move on to there or move off to their own texture or something and it's just this just the realities of working with a set Texel density now to be truthful most times in games for tiling textures this is easy because it doesn't matter where in my islands fall but for uniquely unwrapped props sometimes you have to eyeball things and just be like well that's that looks pretty close and that kind of thing and I'll show you that here in a second so for a quick demonstration of these concepts here's a quick little scene I put together it was just a shelf with some objects sitting on it now to see the current these objects are all separated and you can see they're unwraps or over here on the left hand side there so they're all unwrapped uniquely so let's start with this tabletop and the quickest way to visualize your texture your Texel density is to pull down this viewport option and go to UV textures and pick something like like the medium texture and then you have to enable it but once that's on there moto Thor is on some you know a square texture that you can see what's going on with your UV is actually let's pick a different one let's go with some large this is a yeah that might be easier to see on the video so you can see we've got some stretching or things like that but that's easily fixed if I just go into that object grab this let's relax that out a little bit just to get a better unwrap and a more even density and then I'll repack that okay so even looking at this you can see that we do have some Texel density problems the the density on this on this vase is smaller than what's on the table because these squares are larger than these squares and that kind of thing so to even all that out that's where Texel density comes into play so I'll select the table I just tell to apply the Texel density okay the table looks pretty good I'll select B vase and apply it to that as well now you see how much that shrunk inside of here because it doesn't need all of this 1024 space it only needs this much to match the tabletop and you can see if I get in here these squares are all identical in size so you can see pretty much what the pattern will be we'll apply that there and we'll apply it to the sphere as well so with everything at the same Texel density you can see we have a nice nice and even distribution of squares on the UV map and that will translate to whatever your texture is you put on here now we do have a problem because this is game art and yeah and I can't have a vase that's sitting in the middle of a texture like this with a bunch of that UV space around it that's just not gonna ship so generally what you will do or one thing you can do well there's two options right sorry I'm I'm waffling a little bit but there's two options you can either give that vase a smaller texture maybe give it like a 512 or a 256 or something and so it maintains the Texel density but it's not wasting texture space now the problem with that is the classic problem of when now you get out you know a whole bunch of little textures and the engines constantly swapping out textures when it's rendering and that's slowing everything down the more palatable solution is to put them onto an atlas texture which basically means packing multiple props onto one texture and we'll do that here in a second okay so for our final thing we're gonna merge these props onto the same texture so let's just go select all three of them and I'll tell modo to go ahead and pack them now this obviously not an optimal pack but whatever it's good enough for demonstration purposes now that actually comes out not bad not that but you can see now that those three objects you if they were used you know together pretty often you could have them on one texture and it would be efficient those are the kinds of decisions you mean I did get used to making when you're an environment artist or a prop artist now obviously the Texel density is not correct because I haven't actually said it I just did a default mode of a pack so if I go up here all my settings are there so I hit the apply overall button you see it all kind of shrunk down a little bit and that tells me that there's still too much texture space going on but it's an improvement right let's let's for the fun of it scale the vase up so so it needs more Texel density now you know I hit that button again now they're all this big and I are sorry I repack it so it knows about the size and then I apply overall now you see that my my pack of these three props although it's perfectly even it with the tabletop but everything looks great they're sticking outside of the zero to one space and this is where you kind of have to fudge it sometimes so in this case I would just simply you know grab all of these and tell motor to fit it in there just just all right just kind of put it back in and it's close enough and close enough is kind of a catchphrase with game art you know as long as it looks reasonable it's fine you don't go too far outside the bounds and don't scale things too much but you can fudge it in and out a little bit as you need to and yeah I think that covers that so I think that about covers Texel density for today you know when you're shipping a game there's a lot of realities that creep in but like I'm talking about the ideal here in this video the reality is that generally when you're shipping a real game there's there's LEDs that come in because things aren't fitting into memory and so certain textures are getting flagged for being nipped down for example or textures are getting merged because of you know again memory issues or you know the level designers are taking some of the props and they're scaling them up failing them down and then throwing off the Texel density ratio of the scene and that kind of thing so you're really gonna get it 100% perfect yep but the goal is to get as good as you can and generally in game art as much as I hate to admit it a lot of it is eyeballed but that's just the other realities of production so if you haven't subscribed to the channel please do there's more of these videos coming obviously if you liked the video hit the like button and I'll see you in the next video thanks for watching

Channel: Warren Marshall

Views: 10,661

Keywords: modo, texel density, tutorial, texel, density, texture density, uv, uvs

Id: Za5AIQXwqCs

Length: 14min 0sec (840 seconds)

Published: Mon Aug 20 2018