Texel density and units in depth
polycounter lvl 13
Hi all, trying to improve my understanding of texel density I come across this article https://80.lv/articles/textel-density-tutorial/
Textools method and manual scale method is what I am having dificulty with as you can see in image below. I even made texture with TD spec in Photoshop.
*4 meter wall in background has 1024 resolution texture tiled 4 times as per tutorial. 0 - 1 space is full with UV of this wall (plane) too.
*3 meter wall (UV island in pic below) when set correctly with textool or manually to match TD its scale is way off from 0-1 space. Also (second attempt) since its 3m in height I also applied tilling to it x3 as per tutorial and it covers the entire 0-1 space with perfect TD. It would be perfect if I want to overlap faces on tilling texture but I want unique details on mesh thus required to fit in 0-1 space with 10.24td.
*Now what I dont understand is matching the TD that is on 4 m wall or 1m wall, like the manual method shown in tutorial.
Also I make modular assets with UDK approach 256x512 , 128x64 etc and uniform scale them down to 1, reason being to keep Unity scale and file factor to 1 and in meters. So 256/100 becomes 2.56m wall height etc, I do it this way because in 3ds max working with generic 2.56 units with system units set to meters is very small. I know I can do different settings and play with units more but I doubt it will help understand this issue of TD, at least this method works 100 percent for Unity scale (Unity default cube is exact match with cube made this way inside 3ds max with 100x100x100, scaled down to 1 reset xform)
Textools method and manual scale method is what I am having dificulty with as you can see in image below. I even made texture with TD spec in Photoshop.
*4 meter wall in background has 1024 resolution texture tiled 4 times as per tutorial. 0 - 1 space is full with UV of this wall (plane) too.
*3 meter wall (UV island in pic below) when set correctly with textool or manually to match TD its scale is way off from 0-1 space. Also (second attempt) since its 3m in height I also applied tilling to it x3 as per tutorial and it covers the entire 0-1 space with perfect TD. It would be perfect if I want to overlap faces on tilling texture but I want unique details on mesh thus required to fit in 0-1 space with 10.24td.
*Now what I dont understand is matching the TD that is on 4 m wall or 1m wall, like the manual method shown in tutorial.
Also I make modular assets with UDK approach 256x512 , 128x64 etc and uniform scale them down to 1, reason being to keep Unity scale and file factor to 1 and in meters. So 256/100 becomes 2.56m wall height etc, I do it this way because in 3ds max working with generic 2.56 units with system units set to meters is very small. I know I can do different settings and play with units more but I doubt it will help understand this issue of TD, at least this method works 100 percent for Unity scale (Unity default cube is exact match with cube made this way inside 3ds max with 100x100x100, scaled down to 1 reset xform)
Replies
Also, if it's not a stupid question, why don't you work in centimetres and save yourself doing the conversion?
As for your question nope not supid at all, you can work with centimetres too but for me its just an old habit coming from UDK days where I use grid snaps with texture atlas and generic units/ system units to meters. This way I can quickly export to both UE without scaling or Unity with scale down.
If I'm understanding you right you want unique details but you also want to hit texel density on a given sized texture?
If so, you need to overlap UVs.
Break the UVs up into areas that can tile, be reused, mirrored etc. And ram them into the available space - then do your bakes etc.
It's that or use a bigger texture
Ok perhaps I explained my issue in a wrong way, I even made a tutorial while ago too that pretty much keeps nice td for all the assets.
Also its generally eyeballing your checker texture to have nice even ratio on assets / environments modules, we can add that three stages too as shown in the 80lvl tutorial (foreground, background, player area etc).
What I am not understanding from that tutorial is how in the world you can have 1024 res per meter and have it fit into 0-1 space, note in my example shown above its a 3x3 meter room so its a very small space that should fit in 0-1 space without overlapping the wall UVs. We have examples of whole environments being done with 1x1024 texture atlas for games (while being super crisp) so you can see its creating a conflict of information.
https://www.youtube.com/watch?v=Gxdjc2a7Toc&t=24s
WRT to the room.
Why do you need to keep it in 0-1 space? normally that's not what you do.
In this case the artist is clearly not aiming for a specific texel density (either that or got very lucky) - they simply wanted consistent density as high as they could get at a given texture size. This is fine for standalone assets but not fine for assets that sit with others.
if you need unique UVs you have to either sacrifice texel density or use a bigger texture
If you need to hit texel density you have to tile/share UVs or use a bigger texture
If you need to have a specific texture size you either sacrifice texel density or tile/share UVs
It's similar to the Good-Fast-Cheap, pick two, paradigm. There is no magic trick to get everything, it's a matter of striking a balance with the resources that you have as best as you can.
Right so I get this result with all wall parts of room overlapping (3x3m room height, width, length) it also matches perfectly with the 1x1m plane on right side. I had to tile wall texture 3 times too so that 1meter of wall get 10.24td. Now what I am struggling to understand with this approach is how in the world you make full lavish environments when just a small 3 meter room took over all your texture space with just 10.24td. That paradigm is killing me now cause I am used to making modular environments using texture atlas being made first and then you cut the parts of texture and make a model from it, like this http://www.thiagoklafke.com/modularenvironments.html . I hope it make sense.
Again thanks fellas.
The materials will usually support some sort of vertex painted blending so you can dirty bits up uniquely.
It's possible you're underestimating the number of materials used in a modern game environment. It's not unusual for it to number in the hundreds.
Aha now that is something that make sense, yea I try to keep my material count to as low as possible for optimization but havent seen info on modern day material count (ubisoft, naughty dog, blizzard etc) most we see are modular assets with texture atlas haha.
With systems like that in place you can start to concern yourself more with memory usage, flexibility and ease of authoring.
It's engine dependent of course, which means you have to know what your target engine can do (which means reading)
Also what if you set texture resolution in Photoshop to 10.24 pixels/centimeter on 1024x1024 document.
"He who asks a question is a fool for five minutes; he who does not ask a question remains a fool forever." (in my defense as I am going nuts over this whole TD best for me is if I stick with Texture Atlas approach the good old way lol. Its a chinese proverb I love and was shared by my uni lecturer)
sharing this link as it has usefull info on same subject.
Any lower than 512 per metre starts to look pretty ropey for fps games but you can mitigate against it by using detail maps or just simpler, cleaner surfaces etc.
3pp games are usually a lot more forgiving so you'll see lower densities there.
Basically the ideal is for texels to match pixels at your closest viewing distance, you'll be very lucky to get a memory budget that allows that but if you do a few sums you can work out what the ideal is and start arguing the toss with programmers in an informed way.
Just doing some breakdown of TD including trim parts, notice how you can break trim sheet 1024 into 4 or as many as you like with power of 2. In my example I have 512-256-128-128 from top to bottom.
And if the difference is drastic. Say I have a statue that's 10m tall, I would most likely use multiple layered materials that combine unique baked maps as well as tiling maps + possible detail maps to nail that required texel density. Then It becomes more of planning out the correct materials needed than worrying about the UVs. Or if you are creating tables/drawers etc. you might have a baked atlas texture set for different details, keyholes, hinges etc. and then use face weighting/baked map for the actual wooden parts combined with a tiling texture.
I feel that the usual single texture set and material workflow still works for relatively simple everyday objects but for anything bigger/more complex I'd start planning different materials and reusability, especially if you want to hit that 1024/m texel density.