Obviously you want to make sure that you use as much of your textures as possible, but at some point you have to draw the line and you will never be able to use all of it unless your texturing a square.

I was reacently texturing a prop that used all but 1/4 of a 512x512 texture. Because of its shape and the fact I didn't want to hack it in half with another edge I wasn't able to get a layout that would result in anything better than 1/4 of the texture going unused (even using a non-square).

I think if I had spent more time on it and maybe hacked it up I could have made it use most of the texture, but then it would have been harder to paint and also would have taken more time.

I'm just curious in your opinion, how much unused texture space is acceptable? I know it's not an easy question to answer but I'm just interested to see peoples thought process on this.

Edit: I suppose what I'm asking specifically is how much wasted space is TOO much wasted space. Where would you draw the line and say you need to go back and do something to utilize more of that space?

dont claim it to be wasted just call it contingecy (sp) for later revisions and additions

depends on the forms being use though tbh and as long as you can get the most texel density for the forms, with the space you end up using, I wouldn't call it a bad thing.

pixels aint nothin but a number.

I would probably try shoving something else on that prop texture. Maybe a similar, smaller prop that will be used a lot in the same areas. Or if you have alpha available, use the remaining 1/4 as a space for decals or texture swaps to do a variant of the prop.

1/4 of a 512x512 is quite a lot of space to just waste on nothing at all, IMHO... there's lots you could do with it without having to change your existing prop UVs or texture at all.

^^keep in mind 1/4 of 512 is a full 256x256.^^

Yeah I'm aware it's a lot of space, but the object is really simple so I only have a couple of big pieces that fit into this square. I suppose my only option would have been to hack the object in half and get some pieces that were more closely resembles a square so they would pack better.

I have see this before in HL2 props on street lights for example. They take the very long vertical cylinder and hack it in half so it can fit more easily into the square texture space.

It can just be mind bending to figure out which is going to be the best route to take sometimes. Because adding more verts is not the best thing, but then again neither is wasting texture space.

I don't want to get into the semantics of performance questions because, as we are all aware, its highly dependent on your engine/hardware, but in general do you think its better to add say 20 more verts or waste a 256x256 texture?

Seams like it would just be better to add the extra verts, but then again this also makes things harder to paint.

It sounds like everyone agrees that 1/4 of a texture exceeds the threshold for acceptable waste under any circumstance.

When ever I uv map, people always complain that I waste uv space and that I should go play tetris...
But wasted UV space is wasted memory. If your texture requires such needs then try changing the texture side so that it may fit. Things like a 512x1024 texture and see how it goes.

Yeah I tried this shape with a non-square 512x1024 but it was only slightly improved, and our engine doesn't handle non-sqaure textures very well. I have to manually crunch the UVs when I go to export. This particular model was just annoying usually this issue is fixed by going to a non-square layout.

I actually just pulled up the model and thought about it some more and I think the issue could have been resolved if I had not mirrored part of it. Which would have resulted in a larger piece that would have filled the gap.

Point being I am very sure there is a way to unwrap every model so that you don't waste 1/4 of your texture space. One way or another you can do it. It's just a question of time/skill.

I was just wondering how much was too much. Seams like 1/4 is beyond the threshold so in the future i'll opt to spend more time figuring it out.


Thanks for the replies everyone

yeah i would definitely never waste as much as 1/4 of a texture space. even 1/8 seems like a waste to me, but i've always been a sucker for maximum optimisation

I'd try to find a way to fix it. A couple of extra verts is almost always worth the memory savings of not wasting the space, if you can get it down to a 512x256

I remember from editing quake 3 content that they say that a 256 x 512 was just as expensive as a 512 x512... Is this true for all games or was it just true for their game

I would like to hear the reason for that, probably some terrible old hardware problem or something. Definitely not the case today.

I think it has to do with loading textures in and out of memory? If all textures are the same size its easier to just overwrite one that is not being uses as opposed to looking up the sizes and swapping one that matches. So a 256x512 slides itself into a 512x512 slot in memory so it can be overwritten by another 512x512 easily.

There are probably more efficient ways to handle it all now.

I don't consider it "wasted space" I consider it, "extra space". If I've gotten everything UV'ed proportionally and laid out as well as I can get it, usually I'll be under my polygon budget too so I go ahead and make extra stuff to fill both.

I generally don't waste much space due to filling all the little gaps with other stuff, but doing characters I think you still end up with a lot of unused space between shells because of the funky organic shapes. Not always the case though.

if you've done your job, the asset looks good in game and you are on budget it doesn't matter how much "empty" UV space there is. So what if you have 50% "wasted space". Exactly what are the negative consequences of that? None.

There's a point where the game runs at its target framerate and all budgets are met where if you do any further optimization you're just wasting your time.

Then again it's very rare that you'd be working on the kind of objects that would result in a lot of unused UV space. I don't know what it is about UV's but every time you have an open space you tend to find a UV island that fits it perfectly. I don't know how that works. Must be magic.

I would probably try to take up at least 80%-95% at least, if not just add some text in there for info detail lol. If its absolutely impossible to avoid splitting it up and causing a nasty seam that will ruin the textre then just leave it.

Originally Posted by Sage

I remember from editing quake 3 content that they say that a 256 x 512 was just as expensive as a 512 x512... Is this true for all games or was it just true for their game

I'd imagine that this had something to do with their memory management system - IE if a character was supposed to use one 512x512, that it would budget 512x512 for them even if you were using a smaller map.

There are half the pixels in a 256x512 and so they typically take about half the memory.

Originally Posted by perna

Then again it's very rare that you'd be working on the kind of objects that would result in a lot of unused UV space. I don't know what it is about UV's but every time you have an open space you tend to find a UV island that fits it perfectly. I don't know how that works. Must be magic.

Yes. And UV fairies.

I would just make sure you fill the space with something if you can, as the texture is going to be in memory, you might as well use it rather than having it empty.

and you can't change the UV? 1/4 is too much!

Typically the only time UV-efficiency must be improved is when you could have used a smaller map (saving memory) or when you're not meeting the target pixel density.

Beyond that, any "per cent usage" value is artificial and has no meaning except in your imagination. It's natural for all of us to care about it, since we're technical and we get hung up on that crap. But it has no real-world relevance.

If you make uv-cuts to increase UV-efficiency past the target pixel density, thereby not only wasting time you could have spent working on the material instead but also making the maps harder to texture as well as slower to render as you've increasing the vertex count, I have a relevant link for you. .

I tend to agree with those who aren't too worried about this.

If the asset looks good in the engine and you've got 25% unused UV space, it's not necessarily a problem.

If you're running dangerously close to a memory limit, then I doubt that will be fixed by managing to use the remaining 25% of your UV space, and I'd look for a solution elsewhere.

Alternatively, if you're brave... in case there are repeated areas that have the exact same texture, you could make a portion of your 512x512 texture tileable and assign several overlapped polys to that part of the texture. That might let you squeeze more out of the rest of the real estate.

now your gonna have to post an image of the thing your talking about, so we can see if the UV fairies are working for you. What Per said really is a reckognisable situation, somehow it always works out perfectly. So image please! Or we could turn it into a stupid mini challenge and upload the obj . (or is it all NDA :S)

Originally Posted by Japhir

now your gonna have to post an image of the thing your talking about, so we can see if the UV fairies are working for you. What Per said really is a reckognisable situation, somehow it always works out perfectly. So image please! Or we could turn it into a stupid mini challenge and upload the obj . (or is it all NDA :S)

It's just a simple aircraft freight container which is shaped like the inside of the fuselage of an aircraft. It was close to being a square but not quite. I mirrored part of it which left this gap. The fact that I chose to mirror it was really what left the gap and didn't occur to me at the time.

So I was left trying to fill this gap with 4 separate pieces and all of them were either too big or too small and I kept on being left with about 1/4 of my space being unused.

With the exception of very organic stuff you can almost always unwrap something so that it uses almost all of your texture space, and after going to back to this I was able to do it. The problem was that I had to get the entire thing done in about an hour and a half at the end of the day and didn't want to have to take it home to work on it. It was just a simple little side prop, the kind of thing you really don't want to waste time on.

So really the question was just about time vs wasted space. Sometimes everything clicks and you don't waste space but other times it becomes more of a chore and you have to spend extra time working on something when you could have just moved on and already be working on something else.

you should have made it unique then, like you say

Yeah I know it was a dumb mistake, but it least it spawned the question and I posted here. I feel like this thread has given a nice overview on the issue of time vs UV space usage. So it wasn't a complete waste